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Path The pathname of the mailer
Flags Special flags for this mailer
Sender Rewriting set(s) for sender addresses
Recipient Rewriting set(s) for recipient addresses
Argv An argument vector to pass to this mailer
Eol The end-of-line string for this mailer
Maxsize The maximum message length to this mailer
maxmessages The maximum message deliveries per connection
Linelimit The maximum line length in the message body
Directory The working directory for the mailer
Userid The default user and group id to run as
Nice The nice(2) increment for the mailer
Charset The default character set for 8-bit characters
Type Type information for DSN diagnostics
Wait The maximum time to wait for the mailer
/ The root directory for the mailer
.)b
Only the first character of the field name is checked.
.pp
The following flags may be set in the mailer description.
Any other flags may be used freely
to conditionally assign headers to messages
destined for particular mailers.
Flags marked with (dg
are not interpreted by the
.i sendmail
binary;
these are the conventionally used to correlate to the flags portion
of the
.b H
line.
Flags marked with (dd
apply to the mailers for the sender address
rather than the usual recipient mailers.
.nr ii 4n
.ip a
Run Extended SMTP (ESMTP) protocol (defined in RFCs 1869, 1652, and 1870).
This flag defaults on if the SMTP greeting message includes the word
.q ESMTP .
.ip A
Look up the user part of the address in the alias database.
Normally this is only set for local mailers.
.ip b
Force a blank line on the end of a message.
This is intended to work around some stupid versions of
/bin/mail
that require a blank line, but do not provide it themselves.
It would not normally be used on network mail.
.ip c
Do not include comments in addresses.
This should only be used if you have to work around
a remote mailer that gets confused by comments.
This strips addresses of the form
.q "Phrase <address>"
or
.q "address (Comment)"
down to just
.q address .
.ip C(dd
If mail is
.i received
from a mailer with this flag set,
any addresses in the header that do not have an at sign
(c
.q @ )
after being rewritten by ruleset three
will have the
.q @domain
clause from the sender envelope address
tacked on.
This allows mail with headers of the form:
.(b
From: usera@hosta
To: userb@hostb, userc
.)b
to be rewritten as:
.(b
From: usera@hosta
To: userb@hostb, userc@hosta
.)b
automatically.
However, it doesn't really work reliably.
.ip d
Do not include angle brackets around route-address syntax addresses.
This is useful on mailers that are going to pass addresses to a shell
that might interpret angle brackets as I/O redirection.
.ip D(dg
This mailer wants a
.q Date:
header line.
.ip e
This mailer is expensive to connect to,
so try to avoid connecting normally;
any necessary connection will occur during a queue run.
See also option
.b HoldExpensive .
.ip E
Escape lines beginning with
.q From
in the message with a `>' sign.
.ip f
The mailer wants a
.b -f
.i from
flag,
but only if this is a network forward operation
(i.e.,
the mailer will give an error
if the executing user
does not have special permissions).
.ip F(dg
This mailer wants a
.q From:
header line.
.ip g
Normally,
.i sendmail
sends internally generated email (e.g., error messages)
using the null return address
as required by RFC 1123.
However, some mailers don't accept a null return address.
If necessary,
you can set the
.b g
flag to prevent
.i sendmail
from obeying the standards;
error messages will be sent as from the MAILER-DAEMON
(actually, the value of the
.b $n
macro).
.ip h
Upper case should be preserved in host names
for this mailer.
.ip i
Do User Database rewriting on envelope sender address.
.ip I
This mailer will be speaking SMTP
to another
.i sendmail
*-
as such it can use special protocol features.
This option is not required
(i.e.,
if this option is omitted the transmission will still operate successfully,
although perhaps not as efficiently as possible).
.ip j
Do User Database rewriting on recipients as well as senders.
.ip k
Normally when
.i sendmail
connects to a host via SMTP,
it checks to make sure that this isn't accidently the same host name
as might happen if
.i sendmail
is misconfigured or if a long-haul network interface is set in loopback mode.
This flag disables the loopback check.
It should only be used under very unusual circumstances.
.ip K
Currently unimplemented.
Reserved for chunking.
.ip l
This mailer is local
(i.e.,
final delivery will be performed).
.ip L
Limit the line lengths as specified in RFC821.
This deprecated option should be replaced by the
.b L=
mail declaration.
For historic reasons, the
.b L
flag also sets the
.b 7
flag.
.ip m
This mailer can send to multiple users
on the same host
in one transaction.
When a
.b $u
macro occurs in the
.i argv
part of the mailer definition,
that field will be repeated as necessary
for all qualifying users.
.ip M(dg
This mailer wants a
.q Message-Id:
header line.
.ip n
Do not insert a UNIX-style
.q From
line on the front of the message.
.ip o
Always run as the owner of the recipient mailbox.
Normally
.i sendmail
runs as the sender for locally generated mail
or as
.q daemon
(actually, the user specified in the
.b u
option)
when delivering network mail.
The normal behavior is required by most local mailers,
which will not allow the envelope sender address
to be set unless the mailer is running as daemon.
This flag is ignored if the
.b S
flag is set.
.ip p
Use the route-addr style reverse-path in the SMTP
.q "MAIL FROM:"
command
rather than just the return address;
although this is required in RFC821 section 3.1,
many hosts do not process reverse-paths properly.
Reverse-paths are officially discouraged by RFC 1123.
.ip P(dg
This mailer wants a
.q Return-Path:
line.
.ip q
When an address that resolves to this mailer is verified
(SMTP VRFY command),
generate 250 responses instead of 252 responses.
This will imply that the address is local.
.ip r
Same as
.b f ,
but sends a
.b -r
flag.
.ip R
Open SMTP connections from a
.q secure
port.
Secure ports aren't
(secure, that is)
except on UNIX machines,
so it is unclear that this adds anything.
.ip s
Strip quote characters (" and e) off of the address
before calling the mailer.
.ip S
Don't reset the userid
before calling the mailer.
This would be used in a secure environment
where
.i sendmail
ran as root.
This could be used to avoid forged addresses.
If the
.b U=
field is also specified,
this flag causes the effective user id to be set to that user.
.ip u
Upper case should be preserved in user names
for this mailer.
.ip U
This mailer wants UUCP-style
.q From
lines with the ugly
.q "remote from <host>"
on the end.
.ip w
The user must have a valid account on this machine,
i.e.,
getpwnam
must succeed.
If not,
the mail is bounced.
This is required to get
.q &.forward
capability.
.ip x(dg
This mailer wants a
.q Full-Name:
header line.
.ip X
This mailer want to use the hidden dot algorithm
as specified in RFC821;
basically,
any line beginning with a dot
will have an extra dot prepended
(to be stripped at the other end).
This insures that lines in the message containing a dot
will not terminate the message prematurely.
.ip z
Run Local Mail Transfer Protocol (LMTP)
between
.i sendmail
and the local mailer.
This is a variant on SMTP
defined in RFC 2033
that is specifically designed for delivery to a local mailbox.
.ip 0
Don't look up MX records for hosts sent via SMTP.
.ip 3
Extend the list of characters converted to =XX notation
when converting to Quoted-Printable
to include those that don't map cleanly between ASCII and EBCDIC.
Useful if you have IBM mainframes on site.
.ip 5
If no aliases are found for this address,
pass the address through ruleset 5 for possible alternate resolution.
This is intended to forward the mail to an alternate delivery spot.
.ip 6
Strip headers to seven bits.
.ip 7
Strip all output to seven bits.
This is the default if the
.b L
flag is set.
Note that clearing this option is not
sufficient to get full eight bit data passed through
.i sendmail .
If the
.b 7
option is set, this is essentially always set,
since the eighth bit was stripped on input.
Note that this option will only impact messages
that didn't have 8(->7 bit MIME conversions performed.
.ip 8
If set,
it is acceptable to send eight bit data to this mailer;
the usual attempt to do 8(->7 bit MIME conversions will be bypassed.
.ip 9
If set,
do
.i limited
7(->8 bit MIME conversions.
These conversions are limited to text/plain data.
.ip :
Check addresses to see if they begin
.q :include: ;
if they do, convert them to the
.q *include*
mailer.
.ip |
Check addresses to see if they begin with a `|';
if they do, convert them to the
.q prog
mailer.
.ip /
Check addresses to see if they begin with a `/';
if they do, convert them to the
.q *file*
mailer.
.ip @
Look up addresses in the user database.
.ip %
Do not attempt delivery on initial recipient of a message
or on queue runs
unless the queued message is selected
using one of the -qI/-qR/-qS queue run modifiers
or an ETRN request.
.pp
Configuration files prior to level 6
assume the `A', `w', `5', `:', `|', `/', and `@' options
on the mailer named
.q local .
.pp
The mailer with the special name
.q error
can be used to generate a user error.
The (optional) host field is an exit status to be returned,
and the user field is a message to be printed.
The exit status may be numeric or one of the values
USAGE, NOUSER, NOHOST, UNAVAILABLE, SOFTWARE, TEMPFAIL, PROTOCOL, or CONFIG
to return the corresponding EX_ exit code,
or an enhanced error code as described in RFC 1893,
.ul
Enhanced Mail System Status Codes.
For example, the entry:
.(b
$#error $@ NOHOST $: Host unknown in this domain
.)b
on the RHS of a rule
will cause the specified error to be generated
and the
.q "Host unknown"
exit status to be returned
if the LHS matches.
This mailer is only functional in rulesets 0, 5,
or one of the check_* rulesets.
.pp
The mailer with the special name
.q discard
causes any mail sent to it to be discarded
but otherwise treated as though it were successfully delivered.
.pp
The mailer named
.q local
.i must
be defined in every configuration file.
This is used to deliver local mail,
and is treated specially in several ways.
Additionally, three other mailers named
.q prog ,
.q *file* ,
and
.q *include*
may be defined to tune the delivery of messages to programs,
files,
and :include: lists respectively.
They default to:
.(b
Mprog, P=/bin/sh, F=lsoDq9, T=DNS/RFC822/X-Unix, A=sh -c $u
M*file*, P=[FILE], F=lsDFMPEouq9, T=DNS/RFC822/X-Unix, A=FILE $u
M*include*, P=/dev/null, F=su, A=INCLUDE $u
.)b
.pp
The Sender and Recipient rewriting sets
may either be a simple ruleset id
or may be two ids separated by a slash;
if so, the first rewriting set is applied to envelope
addresses
and the second is applied to headers.
Setting any value zero disables corresponding mailer-specific rewriting.
.pp
The Directory
is actually a colon-separated path of directories to try.
For example, the definition
.q D=$z:/
first tries to execute in the recipient's home directory;
if that is not available,
it tries to execute in the root of the filesystem.
This is intended to be used only on the
.q prog
mailer,
since some shells (such as
.i csh )
refuse to execute if they cannot read the home directory.
Since the queue directory is not normally readable by unprivileged users
.i csh
scripts as recipients can fail.
.pp
The Userid
specifies the default user and group id to run as,
overriding the
.b DefaultUser
option (q.v.).
If the
.b S
mailer flag is also specified,
this user and group will be set as the
effective uid and gid for the process.
This may be given as
.i user:group
to set both the user and group id;
either may be an integer or a symbolic name to be looked up
in the
.i passwd
and
.i group
files respectively.
If only a symbolic user name is specified,
the group id in the
.i passwd
file for that user is used as the group id.
.pp
The Charset field
is used when converting a message to MIME;
this is the character set used in the
Content-Type: header.
If this is not set, the
.b DefaultCharset
option is used,
and if that is not set, the value
.q unknown-8bit
is used.
.b WARNING:
this field applies to the sender's mailer,
not the recipient's mailer.
For example, if the envelope sender address
lists an address on the local network
and the recipient is on an external network,
the character set will be set from the Charset= field
for the local network mailer,
not that of the external network mailer.
.pp
The Type= field
sets the type information
used in MIME error messages
as defined by
RFC 1894.
It is actually three values separated by slashes:
the MTA-type (that is, the description of how hosts are named),
the address type (the description of e-mail addresses),
and the diagnostic type (the description of error diagnostic codes).
Each of these must be a registered value
or begin with
.q X- .
The default is
.q dns/rfc822/smtp .
.pp
The m= field specifies the maximum number of messages to attempt to deliver
on a single SMTP or LMTP connection.
.pp
The /= field specifies a new root directory for the mailer. The path is
macro expanded and then passed to the
.q chroot
system call. The root directory is changed before the Directory field is
consulted or the uid is changed.
.pp
The Wait= field specifies the maximum time to wait for the
mailer to return after sending all data to it.
This applies to mailers that have been forked by
.i sendmail .
.sh 2 "H *- Define Header"
.pp
The format of the header lines that
.i sendmail
inserts into the message
are defined by the
.b H
line.
The syntax of this line is:
.(b F
.b H [c
.b ? c
.i mflags c
.b ? |c
.i ${macro} c
.b ]c
.i hname c
.b :
.i htemplate
.)b
Continuation lines in this spec
are reflected directly into the outgoing message.
The
.i htemplate
is macro-expanded before insertion into the message.
If the
.i mflags
(surrounded by question marks)
are specified,
at least one of the specified flags
must be stated in the mailer definition
for this header to be automatically output.
If a
.i ${macro}
is specified,
the header will be automatically output
if the macro is set.
The macro may be set using any of the normal methods,
including using the
.b macro
storage map in a ruleset.
If one of these headers is in the input
it is reflected to the output
regardless of these flags or macros.
.pp
Some headers have special semantics
that will be described later.
.pp
A secondary syntax allows validation of headers as they are being read.
To enable validation, use:
.(b
.b H c
.i Header c
.b ": $>" c
.i Ruleset
.b H c
.i Header c
.b ": $>+" c
.i Ruleset
.)b
The indicated
.i Ruleset
is called for the specified
.i Header ,
and can return
.b $#error
to reject the message or
.b $#discard
to discard the message
(as with the other
.b check_ *
rulesets).
The header is treated as a structured field,
that is,
comments (in parentheses) are deleted before processing,
unless the second form
.b $>+
is used.
.pp
For example, the configuration lines:
.(b
HMessage-Id: $>CheckMessageId
SCheckMessageId
R< $+ @ $+ > $@ OK
R$* $#error $: Illegal Message-Id header
.)b
would refuse any message that had a Message-Id: header of any of the
following forms:
.(b
Message-Id: <>
Message-Id: some text
Message-Id: <legal text@domain> extra crud
.)b
A default ruleset that is called for headers which don't have a
specific ruleset defined for them can be specified by:
.(b
.b H c
.i * c
.b ": $>" c
.i Ruleset
.)b
or
.(b
.b H c
.i * c
.b ": $>+" c
.i Ruleset
.)b
.sh 2 "O *- Set Option"
.pp
There are a number of
global
options that
can be set from a configuration file.
Options are represented by full words;
some are also representable as single characters
for back compatibility.
The syntax of this line is:
.(b F
.b O
.i option c
.b = c
.i value
.)b
This sets option
.i option
to be
.i value .
Note that there
.i must
be a space between the letter `O' and the name of the option.
An older version is:
.(b F
.b O c
.i o|value
.)b
where the option
.i o
is a single character.
Depending on the option,
.i value
may be a string, an integer,
a boolean
(with legal values
.q t ,
.q T ,
.q f ,
or
.q F ;
the default is TRUE),
or
a time interval.
.pp
The options supported (with the old, one character names in brackets) are:
.nr ii 1i
.ip "AliasFile=fIspec, spec, ...fP"
[A]
Specify possible alias file(s).
Each
.i spec
should be in the format
``c
.i class c
.b :
.i file ''
where
.i class c
.b :
is optional and defaults to ``implicit''.
Depending on how
.i sendmail
is compiled, valid classes are
.q implicit
(search through a compiled-in list of alias file types,
for back compatibility),
.q hash
(if
.sm NEWDB
is specified),
.q dbm
(if
.sm NDBM
is specified),
.q stab
(internal symbol table *- not normally used
unless you have no other database lookup),
or
.q nis
(if
.sm NIS
is specified).
If a list of
.i spec s
are provided,
.i sendmail
searches them in order.
.ip AliasWait=fItimeoutfP
[a]
If set,
wait up to
.i timeout
(units default to minutes)
for an
.q @:@
entry to exist in the alias database
before starting up.
If it does not appear in the
.i timeout
interval
rebuild the database
(if the
.b AutoRebuildAliases
option is also set)
or issue a warning.
.ip AllowBogusHELO
[no short name]
If set, allow HELO SMTP commands that don't include a host name.
Setting this violates RFC 1123 section 5.2.5,
but is necessary to interoperate with several SMTP clients.
If there is a value, it is still checked for legitimacy.
.ip AuthMechanisms
[no short name]
List of authentication mechanisms for AUTH (separated by spaces).
The advertised list of authentication mechanisms will be the
intersection of this list and the list of available mechanisms as
determined by the CYRUS SASL library.
.ip AuthOptions
[no short name]
When to use the AUTH= parameter for the MAIL FROM command;
.(b
.ta 1i
T Try when SMTP AUTH available (default).
A Only when authentication succeeded.
.)b
.ip AutoRebuildAliases
[D]
If set,
rebuild the alias database if necessary and possible.
The rebuild will happen the next time an alias is looked up.
If this option is not set,
.i sendmail
will never rebuild the alias database
unless explicitly requested
using
.b -bi .
.b NOTE :
There is a potential for a denial of service attack if this is set.
This option is deprecated and
will be removed from a future version.
.ip BlankSub=fIcfP
[B]
Set the blank substitution character to
.i c .
Unquoted spaces in addresses are replaced by this character.
Defaults to space (i.e., no change is made).
.ip CheckAliases
[n]
Validate the RHS of aliases when rebuilding the alias database.
.ip CheckpointInterval=fINfP
[C]
Checkpoints the queue every
.i N
(default 10)
addresses sent.
If your system crashes during delivery to a large list,
this prevents retransmission to any but the last
.I N
recipients.
.ip ClassFactor=fIfactfP
[z]
The indicated
.i fact or
is multiplied by the message class
(determined by the Precedence: field in the user header
and the
.b P
lines in the configuration file)
and subtracted from the priority.
Thus, messages with a higher Priority: will be favored.
Defaults to 1800.
.ip ClientPortOptions=fIoptionsfP
[O]
Set client SMTP options.
The options are
.i key=value
pairs separated by commas.
Known keys are:
.(b
.ta 1i
Port Name/number of source port for connection (defaults to any free port)
Addr Address mask (defaults INADDR_ANY)
Family Address family (defaults to INET)
SndBufSize Size of TCP send buffer
RcvBufSize Size of TCP receive buffer
Modifier Options (flags) for the daemon
.)b
The
.i Addr ess
mask may be a numeric address in dot notation
or a network name.
.i Modifier
can be the following character:
.(b
.ta 1i
h use name of interface for HELO command
.)b
If ``h'' is set, the name corresponding to the outgoing interface
address (whether chosen via the Connection parameter or
the default) is used for the HELO/EHLO command.
.ip ColonOkInAddr
[no short name]
If set, colons are acceptable in e-mail addresses
(e.g.,
.q host:user ).
If not set, colons indicate the beginning of a RFC 822 group construct
(c
.q "groupname: member1, member2, ... memberN;" ).
Doubled colons are always acceptable
(c
.q nodename::user )
and proper route-addr nesting is understood
(c
.q <@relay:user@host> ).
Furthermore, this option defaults on if the configuration version level
is less than 6 (for back compatibility).
However, it must be off for full compatibility with RFC 822.
.ip ConnectionCacheSize=fINfP
[k]
The maximum number of open connections that will be cached at a time.
The default is one.
This delays closing the current connection until
either this invocation of
.i sendmail
needs to connect to another host
or it terminates.
Setting it to zero defaults to the old behavior,
that is, connections are closed immediately.
Since this consumes file descriptors,
the connection cache should be kept small:
4 is probably a practical maximum.
.ip ConnectionCacheTimeout=fItimeoutfP
[K]
The maximum amount of time a cached connection will be permitted to idle
without activity.
If this time is exceeded,
the connection is immediately closed.
This value should be small (on the order of ten minutes).
Before
.i sendmail
uses a cached connection,
it always sends a RSET command
to check the connection;
if this fails, it reopens the connection.
This keeps your end from failing if the other end times out.
The point of this option is to be a good network neighbor
and avoid using up excessive resources
on the other end.
The default is five minutes.
.ip ConnectOnlyTo=fIaddressfP
[no short name]
This can be used to
override the connection address (for testing purposes).
.ip ConnectionRateThrottle=fINfP
[no short name]
If set to a positive value,
allow no more than
.i N
incoming daemon connections in a one second period.
This is intended to flatten out peaks
and allow the load average checking to cut in.
Defaults to zero (no limits).
.ip ControlSocketName=fInamefP
[no short name]
Name of the control socket for daemon management.
A running
.i sendmail
daemon can be controlled through this named socket.
Available commands are:
.i help,
.i restart,
.i shutdown,
and
.i status.
The
.i status
command returns the current number of daemon children,
the maximum number of daemon children,
the free disk space (in blocks) of the queue directory,
and the load average of the machine expressed as an integer.
If not set, no control socket will be available.
Solaris and pre-4.4BSD kernel users should see the note in sendmail/README .
.ip DaemonPortOptions=fIoptionsfP
[O]
Set server SMTP options.
The options are
.i key=value
pairs.
Known keys are:
.(b
.ta 1i
Name User-definable name for the daemon (defaults to "Daemon#")
Port Name/number of listening port (defaults to "smtp")
Addr Address mask (defaults INADDR_ANY)
Family Address family (defaults to INET)
Listen Size of listen queue (defaults to 10)
Modifier Options (flags) for the daemon
SndBufSize Size of TCP send buffer
RcvBufSize Size of TCP receive buffer
.)b
The
.i Name
field is used for error messages and logging.
The
.i Addr ess
mask may be a numeric address in dot notation
or a network name.
.i Modifier
can be a sequence (without any delimiters)
of the following characters:
.(b
.ta 1i
a require authentication
b bind to interface through which mail has been received
c perform hostname canonification (.cf)
f require fully qualified hostname (.cf)
u allow unqualified addresses (.cf)
C don't perform hostname canonification
E disallow ETRN (see RFC 2476)
.)b
That is, one way to specify a message submission agent (MSA) that
requires authentication is:
.(b
O DaemonPortOptions=Name=MSA, Port=587, M=Ea
.)b
The modifiers that are marked with "(.cf)" have only
effect in the standard configuration file, in which
they are available via
.b ${daemon_flags} .
The flags ``c'' and ``C'' can change the default for
hostname canonification in the
.i sendmail.cf
file.
See the relevant documentation for
.sm FEATURE(nocanonify) .
The modifier ``f'' disallows addresses of the form
.b user@host
unless they are submitted directly.
The flag ``u'' allows unqualified sender addresses.
``b'' forces sendmail to bind to the interface
through which the e-mail has been
received for the outgoing connection.
.b WARNING:
Use ``b''
only if outgoing mail can be routed through the incoming connection's
interface to its destination. No attempt is made to catch problems due to a
misconfiguration of this parameter, use it only for virtual hosting
where each virtual interface can connect to every possible location.
This will also override possible settings via
.b ClientPortOptions.
Note,
.i sendmail
will listen on a new socket
for each occurence of the DaemonPortOptions option
in a configuration file.
.ip DefaultAuthInfo
[no short name]
Filename that contains default authentication information for outgoing
connections. This file must contain the user id, the authorization id,
the password (plain text), and the realm to use
on separate lines and must be readable by
root (or the trusted user) only.
If no realm is specified,
.b $j
is used.
.ip DefaultCharSet=fIcharsetfP
[no short name]
When a message that has 8-bit characters but is not in MIME format
is converted to MIME
(see the EightBitMode option)
a character set must be included in the Content-Type: header.
This character set is normally set from the Charset= field
of the mailer descriptor.
If that is not set, the value of this option is used.
If this option is not set, the value
.q unknown-8bit
is used.
.ip DataFileBufferSize=fIthresholdfP
[no short name]
Set the
.i threshold ,
in bytes,
before a memory-based
queue data file
becomes disk-based.
The default is 4096 bytes.
.ip DeadLetterDrop=fIfilefP
[no short name]
Defines the location of the system-wide dead.letter file,
formerly hardcoded to /usr/tmp/dead.letter.
If this option is not set (the default),
sendmail will not attempt to save to a system-wide dead.letter file
in the event
it can not bounce the mail to the user or postmaster.
Instead, it will rename the qf file
as it has in the past
when the dead.letter file could not be opened.
.ip DefaultUser=fIuser:groupfP
[u]
Set the default userid for mailers to
.i user:group .
If
.i group
is omitted and
.i user
is a user name
(as opposed to a numeric user id)
the default group listed in the /etc/passwd file for that user is used
as the default group.
Both
.i user
and
.i group
may be numeric.
Mailers without the
.i S
flag in the mailer definition
will run as this user.
Defaults to 1:1.
The value can also be given as a symbolic user name.**
.(f
**The old
.b g
option has been combined into the
.b DefaultUser
option.
.)f
.ip DeliveryMode=fIxfP
[d]
Deliver in mode
.i x .
Legal modes are:
.(b
.ta 4n
i Deliver interactively (synchronously)
b Deliver in background (asynchronously)
q Just queue the message (deliver during queue run)
d Defer delivery and all map lookups (deliver during queue run)
.)b
Defaults to ``b'' if no option is specified,
``i'' if it is specified but given no argument
(i.e., ``Od'' is equivalent to ``Odi'').
The
.b -v
command line flag sets this to
.b i .
.ip DialDelay=fIsleeptimefP
[no short name]
Dial-on-demand network connections can see timeouts
if a connection is opened before the call is set up.
If this is set to an interval and a connection times out
on the first connection being attempted
.i sendmail
will sleep for this amount of time and try again.
This should give your system time to establish the connection
to your service provider.
Units default to seconds, so
.q DialDelay=5
uses a five second delay.
Defaults to zero
(no retry).
.ip DontBlameSendmail=fIoption,option,...fP
[no short name]
In order to avoid possible cracking attempts
caused by world- and group-writable files and directories,
.i sendmail
does paranoid checking when opening most of its support files.
If for some reason you absolutely must run with,
for example,
a group-writable
.i /etc
directory,
then you will have to turn off this checking
(at the cost of making your system more vulnerable to attack).
The arguments are individual options that turn off checking:
.(b
Safe
AssumeSafeChown
ClassFileInUnsafeDirPath
DontWarnForwardFileInUnsafeDirPath
ErrorHeaderInUnsafeDirPath
FileDeliveryToHardLink
FileDeliveryToSymLink
ForwardFileInUnsafeDirPath
ForwardFileInUnsafeDirPathSafe
ForwardFileIngroupWritableDirPath
GroupWritableAliasFile
GroupWritableDirPathSafe
GroupWritableForwardFileSafe
GroupWritableIncludeFileSafe
HelpFileinUnsafeDirPath
IncludeFileInUnsafeDirPath
IncludeFileInUnsafeDirPathSafe
IncludeFileIngroupWritableDirPath
LinkedAliasFileInWritableDir
LinkedClassFileInWritableDir
LinkedForwardFileInWritableDir
LinkedIncludeFileInWritableDir
LinkedMapInWritableDir
LinkedServiceSwitchFileInWritableDir
MapInUnsafeDirPath
NonRootSafeAddr
RunProgramInUnsafeDirPath
RunWritableProgram
TrustStickyBit
WorldWritableAliasFile
WriteMapToHardLink
WriteMapToSymLink
WriteStatsToHardLink
WriteStatsToSymLink
.)b
.b Safe
is the default.
The details of these flags are described above.
."XXX should have more here!!! XXX
.b "Use of this option is not recommended."
.ip DontExpandCnames
[no short name]
The standards say that all host addresses used in a mail message
must be fully canonical.
For example, if your host is named
.q Cruft.Foo.ORG
and also has an alias of
.q FTP.Foo.ORG ,
the former name must be used at all times.
This is enforced during host name canonification
($[ ... $] lookups).
If this option is set, the protocols are ignored and the
.q wrong
thing is done.
However, the IETF is moving toward changing this standard,
so the behavior may become acceptable.
Please note that hosts downstream may still rewrite the address
to be the true canonical name however.
.ip DontInitGroups
[no short name]
If set,
.i sendmail
will avoid using the initgroups(3) call.
If you are running NIS,
this causes a sequential scan of the groups.byname map,
which can cause your NIS server to be badly overloaded in a large domain.
The cost of this is that the only group found for users
will be their primary group (the one in the password file),
which will make file access permissions somewhat more restrictive.
Has no effect on systems that don't have group lists.
.ip DontProbeInterfaces
[no short name]
.i Sendmail
normally finds the names of all interfaces active on your machine
when it starts up
and adds their name to the
.b $=w
class of known host aliases.
If you have a large number of virtual interfaces
or if your DNS inverse lookups are slow
this can be time consuming.
This option turns off that probing.
However, you will need to be certain to include all variant names
in the
.b $=w
class by some other mechanism.
.ip DontPruneRoutes
[R]
Normally,
.i sendmail
tries to eliminate any unnecessary explicit routes
when sending an error message
(as discussed in RFC 1123 (sc 5.2.6).
For example,
when sending an error message to
.(b
<@known1,@known2,@known3:user@unknown>
.)b
.i sendmail
will strip off the
.q @known1,@known2
in order to make the route as direct as possible.
However, if the
.b R
option is set, this will be disabled,
and the mail will be sent to the first address in the route,
even if later addresses are known.
This may be useful if you are caught behind a firewall.
.ip DoubleBounceAddress=fIerror-addressfP
[no short name]
If an error occurs when sending an error message,
send the error report
(termed a
.q "double bounce"
because it is an error
.q bounce
that occurs when trying to send another error
.q bounce )
to the indicated address.
The address is macro expanded
at the time of delivery.
If not set, defaults to
.q postmaster .
.ip EightBitMode=fIactionfP
[8]
Set handling of eight-bit data.
There are two kinds of eight-bit data:
that declared as such using the
.b BODY=8BITMIME
ESMTP declaration or the
.b -B8BITMIME
command line flag,
and undeclared 8-bit data, that is,
input that just happens to be eight bits.
There are three basic operations that can happen:
undeclared 8-bit data can be automatically converted to 8BITMIME,
undeclared 8-bit data can be passed as-is without conversion to MIME
(``just send 8''),
and declared 8-bit data can be converted to 7-bits
for transmission to a non-8BITMIME mailer.
The possible
.i action s
are:
.(b
." r Reject undeclared 8-bit data;
." don't convert 8BITMIME(->7BIT (``reject'')
s Reject undeclared 8-bit data (``strict'')
." do convert 8BITMIME(->7BIT (``strict'')
." c Convert undeclared 8-bit data to MIME;
." don't convert 8BITMIME(->7BIT (``convert'')
m Convert undeclared 8-bit data to MIME (``mime'')
." do convert 8BITMIME(->7BIT (``mime'')
." j Pass undeclared 8-bit data;
." don't convert 8BITMIME(->7BIT (``just send 8'')
p Pass undeclared 8-bit data (``pass'')
." do convert 8BITMIME(->7BIT (``pass'')
." a Adaptive algorithm: see below
.)b
."The adaptive algorithm is to accept 8-bit data,
."converting it to 8BITMIME only if the receiver understands that,
."otherwise just passing it as undeclared 8-bit data;
."8BITMIME(->7BIT conversions are done.
In all cases properly declared 8BITMIME data will be converted to 7BIT
as needed.
.ip ErrorHeader=fIfile-or-messagefP
[E]
Prepend error messages with the indicated message.
If it begins with a slash,
it is assumed to be the pathname of a file
containing a message (this is the recommended setting).
Otherwise, it is a literal message.
The error file might contain the name, email address, and/or phone number
of a local postmaster who could provide assistance
to end users.
If the option is missing or null,
or if it names a file which does not exist or which is not readable,
no message is printed.
.ip ErrorMode=fIxfP
[e]
Dispose of errors using mode
.i x .
The values for
.i x
are:
.(b
p Print error messages (default)
q No messages, just give exit status
m Mail back errors
w Write back errors (mail if user not logged in)
e Mail back errors and give zero exit stat always
.)b
.ip FallbackMXhost=fIfallbackhostfP
[V]
If specified, the
.i fallbackhost
acts like a very low priority MX
on every host.
This is intended to be used by sites with poor network connectivity.
Messages which are undeliverable due to temporary address failures
(e.g., DNS failure)
also go to the FallBackMX host.
.ip ForkEachJob
[Y]
If set,
deliver each job that is run from the queue in a separate process.
Use this option if you are short of memory,
since the default tends to consume considerable amounts of memory
while the queue is being processed.
.ip ForwardPath=fIpathfP
[J]
Set the path for searching for users' .forward files.
The default is
.q $z/.forward .
Some sites that use the automounter may prefer to change this to
.q /var/forward/$u
to search a file with the same name as the user in a system directory.
It can also be set to a sequence of paths separated by colons;
.i sendmail
stops at the first file it can successfully and safely open.
For example,
.q /var/forward/$u:$z/.forward
will search first in /var/forward/c
.i username
and then in
.i ~username /.forward
(but only if the first file does not exist).
.ip HelpFile=fIfilefP
[H]
Specify the help file
for SMTP.
If no file name is specified, "helpfile" is used.
.ip HoldExpensive
[c]
If an outgoing mailer is marked as being expensive,
don't connect immediately.
This requires that queueing be compiled in,
since it will depend on a queue run process to
actually send the mail.
.ip HostsFile=fIpathfP
[no short name]
The path to the hosts database,
normally
.q /etc/hosts .
This option is only consulted when sendmail
is canonifying addresses,
and then only when
.q files
is in the
.q hosts
service switch entry.
In particular, this file is
.i never
used when looking up host addresses;
that is under the control of the system
.i gethostbyname (3)
routine.
.ip HostStatusDirectory=fIpathfP
[no short name]
The location of the long term host status information.
When set,
information about the status of hosts
(e.g., host down or not accepting connections)
will be shared between all
.i sendmail
processes;
normally, this information is only held within a single queue run.
This option requires a connection cache of at least 1 to function.
If the option begins with a leading `/',
it is an absolute pathname;
otherwise,
it is relative to the mail queue directory.
A suggested value for sites desiring persistent host status is
.q &.hoststat
(i.e., a subdirectory of the queue directory).
.ip IgnoreDots
[i]
Ignore dots in incoming messages.
This is always disabled (that is, dots are always accepted)
when reading SMTP mail.
.ip LDAPDefaultSpec=fIspecfP
[no short name]
Sets a default map specification for LDAP maps.
The value should only contain LDAP specific settings
such as
.q "-h host -p port -d bindDN" .
The settings will be used for all LDAP maps
unless the individual map specification overrides a setting.
This option should be set before any LDAP maps are defined.
.ip LogLevel=fInfP
[L]
Set the log level to
.i n .
Defaults to 9.
.ip MfIx|valuefP
[no long version]
Set the macro
.i x
to
.i value .
This is intended only for use from the command line.
The
.b -M
flag is preferred.
.ip MatchGECOS
[G]
Allow fuzzy matching on the GECOS field.
If this flag is set,
and the usual user name lookups fail
(that is, there is no alias with this name and a
.i getpwnam
fails),
sequentially search the password file
for a matching entry in the GECOS field.
This also requires that MATCHGECOS
be turned on during compilation.
This option is not recommended.
.ip MaxAliasRecursion=fINfP
[no short name]
The maximum depth of alias recursion (default: 10).
.ip MaxDaemonChildren=fINfP
[no short name]
If set,
.i sendmail
will refuse connections when it has more than
.i N
children processing incoming mail.
This does not limit the number of outgoing connections.
If not set, there is no limit to the number of children --
that is, the system load averaging controls this.
.ip MaxHeadersLength=fINfP
[no short name]
The maximum length of the sum of all headers.
This can be used to prevent a denial of service attack.
The default is no limit.
.ip MaxHopCount=fINfP
[h]
The maximum hop count.
Messages that have been processed more than
.i N
times are assumed to be in a loop and are rejected.
Defaults to 25.
.ip MaxHostStatAge=fIagefP
[no short name]
Not yet implemented.
This option specifies how long host status information will be retained.
For example, if a host is found to be down,
connections to that host will not be retried for this interval.
The units default to minutes.
.ip MaxMessageSize=fINfP
[no short name]
Specify the maximum message size
to be advertised in the ESMTP EHLO response.
Messages larger than this will be rejected.
.ip MaxMimeHeaderLength=fIN[/M]fP
[no short name]
Sets the maximum length of certain MIME header field values
to
.i N
characters.
For some of these headers which take parameters,
the maximum length of each parameter is set to
.i M
if specified. If
.i /M
is not specified, one half of
.i N
will be used.
By default,
these values are 0, meaning no checks are done.
.ip MaxQueueRunSize=fINfP
[no short name]
The maximum number of jobs that will be processed
in a single queue run.
If not set, there is no limit on the size.
If you have very large queues or a very short queue run interval
this could be unstable.
However, since the first
.i N
jobs in queue directory order are run (rather than the
.i N
highest priority jobs)
this should be set as high as possible to avoid
.q losing
jobs that happen to fall late in the queue directory.
.ip MaxRecipientsPerMessage=fINfP
[no short name]
The maximum number of recipients that will be accepted per message
in an SMTP transaction.
Note: setting this too low can interfere with sending mail from
MUAs that use SMTP for initial submission.
If not set, there is no limit on the number of recipients per envelope.
.ip MeToo
[m]
Send to me too,
even if I am in an alias expansion.
.ip MinFreeBlocks=fINfP
[b]
Insist on at least
.i N
blocks free on the filesystem that holds the queue files
before accepting email via SMTP.
If there is insufficient space
.i sendmail
gives a 452 response
to the MAIL command.
This invites the sender to try again later.
.ip MinQueueAge=fPagefP
[no short name]
Don't process any queued jobs
that have been in the queue less than the indicated time interval.
This is intended to allow you to get responsiveness
by processing the queue fairly frequently
without thrashing your system by trying jobs too often.
The default units are minutes.
.ip MustQuoteChars=fIsfP
[no short name]
Sets the list of characters that must be quoted if used in a full name
that is in the phrase part of a ``phrase <address>'' syntax.
The default is ``'.''.
The characters ``@,;:e()[]'' are always added to this list.
.ip NoRecipientAction
[no short name]
The action to take when you receive a message that has no valid
recipient headers (To:, Cc:, Bcc:, or Apparently-To: (em
the last included for back compatibility with old
.i sendmail s).
It can be
.b None
to pass the message on unmodified,
which violates the protocol,
.b Add-To
to add a To: header with any recipients it can find in the envelope
(which might expose Bcc: recipients),
.b Add-Apparently-To
to add an Apparently-To: header
(this is only for back-compatibility
and is officially deprecated),
.b Add-To-Undisclosed
to add a header
.q "To: undisclosed-recipients:;"
to make the header legal without disclosing anything,
or
.b Add-Bcc
to add an empty Bcc: header.
.ip OldStyleHeaders
[o]
Assume that the headers may be in old format,
i.e.,
spaces delimit names.
This actually turns on
an adaptive algorithm:
if any recipient address contains a comma, parenthesis,
or angle bracket,
it will be assumed that commas already exist.
If this flag is not on,
only commas delimit names.
Headers are always output with commas between the names.
Defaults to off.
.ip OperatorChars=fIcharlistfP
[$o macro]
The list of characters that are considered to be
.q operators ,
that is, characters that delimit tokens.
All operator characters are tokens by themselves;
sequences of non-operator characters are also tokens.
White space characters separate tokens
but are not tokens themselves (em for example,
.q AAA.BBB
has three tokens, but
.q "AAA BBB"
has two.
If not set, OperatorChars defaults to
.q &.|:|@|[|] ;
additionally, the characters
.q (|)|<|>|,|;
are always operators.
Note that OperatorChars must be set in the
configuration file before any rulesets.
.ip PidFile=fIfilenamefP
[no short name]
Filename of the pid file.
(default is _PATH_SENDMAILPID).
The
.i filename
is macro-expanded before it is opened.
.ip PostmasterCopy=fIpostmasterfP
[P]
If set,
copies of error messages will be sent to the named
.i postmaster .
Only the header of the failed message is sent.
Since most errors are user problems,
this is probably not a good idea on large sites,
and arguably contains all sorts of privacy violations,
but it seems to be popular with certain operating systems vendors.
The address is macro expanded
at the time of delivery.
Defaults to no postmaster copies.
.ip PrivacyOptions=fI|opt,opt,...fP
[p]
Set the privacy
.i opt ions.
``Privacy'' is really a misnomer;
many of these are just a way of insisting on stricter adherence
to the SMTP protocol.
The
.i opt ions
can be selected from:
.(b
.ta w'needvrfyhelo'u+3n
public Allow open access
needmailhelo Insist on HELO or EHLO command before MAIL
needexpnhelo Insist on HELO or EHLO command before EXPN
noexpn Disallow EXPN entirely
needvrfyhelo Insist on HELO or EHLO command before VRFY
novrfy Disallow VRFY entirely
noetrn Disallow ETRN entirely
noverb Disallow VERB entirely
restrictmailq Restrict mailq command
restrictqrun Restrict -q command line flag
noreceipts Don't return success DSNs**
nobodyreturn Don't return the body of a message with DSNs
goaway Disallow essentially all SMTP status queries
authwarnings Put X-Authentication-Warning: headers in messages
.)b
.(f
**N.B.:
the
.b noreceipts
flag turns off support for RFC 1891
(Delivery Status Notification).
.)f
The
.q goaway
pseudo-flag sets all flags except
.q noreceipts ,
.q restrictmailq ,
.q restrictqrun ,
.q noetrn ,
and
.q nobodyreturn .
If mailq is restricted,
only people in the same group as the queue directory
can print the queue.
If queue runs are restricted,
only root and the owner of the queue directory
can run the queue.
Authentication Warnings add warnings about various conditions
that may indicate attempts to spoof the mail system,
such as using an non-standard queue directory.
.ip ProcessTitlePrefix=fIstringfP
[no short name]
Prefix the process title shown on 'ps' listings with
.i string .
The
.i string
will be macro processed.
.ip QueueDirectory=fIdirfP
[Q]
Use the named
.i dir
as the queue directory.
To use multiple queues, supply a value ending with an asterisk.
For example,
.i /var/spool/mqueue/q*
will use all of the directories or symbolic links to directories
beginning with
.i q
in
.i /var/spool/mqueue
as queue directories.
Do not change the queue directory structure
while sendmail is running.
.ip QueueFactor=fIfactorfP
[q]
Use
.i factor
as the multiplier in the map function
to decide when to just queue up jobs rather than run them.
This value is divided by the difference between the current load average
and the load average limit
(c
.b QueueLA
option)
to determine the maximum message priority
that will be sent.
Defaults to 600000.
.ip QueueLA=fILAfP
[x]
When the system load average exceeds
.i LA ,
just queue messages
(i.e., don't try to send them).
Defaults to 8 multiplied by
the number of processors online on the system
(if that can be determined).
.ip QueueSortOrder=fIalgorithmfP
[no short name]
Sets the
.i algorithm
used for sorting the queue.
Only the first character of the value is used.
Legal values are
.q host
(to order by the name of the first host name of the first recipient),
.q filename
(to order by the name of the queue file name),
.q time
(to order by the submission time),
and
.q priority
(to order by message priority).
Host ordering makes better use of the connection cache,
but may tend to process low priority messages
that go to a single host
over high priority messages that go to several hosts;
it probably shouldn't be used on slow network links.
Filename ordering saves the overhead of
reading all of the queued items
before starting the queue run.
Time ordering is almost always a bad idea,
since it allows large, bulk mail to go out
before smaller, personal mail,
but may have applicability on some hosts with very fast connections.
Priority ordering is the default.
.ip QueueTimeout=fItimeoutfP
[T]
A synonym for
.q Timeout.queuereturn .
Use that form instead of the
.q QueueTimeout
form.
.ip ResolverOptions=fIoptionsfP
[I]
Set resolver options.
Values can be set using
.b + c
.i flag
and cleared using
.b - c
.i flag ;
the
.i flag s
can be
.q debug ,
.q aaonly ,
.q usevc ,
.q primary ,
.q igntc ,
.q recurse ,
.q defnames ,
.q stayopen ,
or
.q dnsrch .
The string
.q HasWildcardMX
(without a
.b +
or
.b - )
can be specified to turn off matching against MX records
when doing name canonifications.
.b N.B.
Prior to 8.7,
this option indicated that the name server be responding
in order to accept addresses.
This has been replaced by checking to see
if the
.q dns
method is listed in the service switch entry for the
.q hosts
service.
.ip RrtImpliesDsn
[R]
If this option is set, a
.q Return-Receipt-To:
header causes the request of a DSN, which is sent to
the envelope sender as required by RFC1891,
not to the address given in the header.
.ip RunAsUser=fIuserfP
[no short name]
The
.i user
parameter may be a user name
(looked up in
.i /etc/passwd )
or a numeric user id;
either form can have
.q ":group"
attached
(where group can be numeric or symbolic).
If set to a non-zero (non-root) value,
.i sendmail
will change to this user id shortly after startup**.
.(f
**When running as a daemon,
it changes to this user after accepting a connection
but before reading any
.sm SMTP
commands.
.)f
This avoids a certain class of security problems.
However, this means that all
.q &.forward
and
.q :include:
files must be readable by the indicated
.i user ,
and on systems that don't support the saved uid bit properly,
all files to be written must be writable by
.i user
and all file and program deliveries will be marked unsafe
unless the option
.b DontBlameSendmail=NonRootAddrSafe
is set,
in which case the delivery will be done as
.i user .
It is also incompatible with the
.b SafeFileEnvironment
option.
In other words, it may not actually add much to security on an average system,
and may in fact detract from security
(because other file permissions must be loosened).
However, it should be useful on firewalls and other
places where users don't have accounts and the aliases file is
well constrained.
.ip RecipientFactor=fIfactfP
[y]
The indicated
.i fact or
is added to the priority (thus
.i lowering
the priority of the job)
for each recipient,
i.e., this value penalizes jobs with large numbers of recipients.
Defaults to 30000.
.ip RefuseLA=fILAfP
[X]
When the system load average exceeds
.i LA ,
refuse incoming SMTP connections.
Defaults to 12 multiplied by
the number of processors online on the system
(if that can be determined).
.ip RetryFactor=fIfactfP
[Z]
The
.i fact or
is added to the priority
every time a job is processed.
Thus,
each time a job is processed,
its priority will be decreased by the indicated value.
In most environments this should be positive,
since hosts that are down are all too often down for a long time.
Defaults to 90000.
.ip SafeFileEnvironment=fIdirfP
[no short name]
If this option is set,
.i sendmail
will do a
.i chroot (2)
call into the indicated
.i dir ectory
before doing any file writes.
If the file name specified by the user begins with
.i dir ,
that partial path name will be stripped off before writing,
so (for example)
if the SafeFileEnvironment variable is set to
.q /safe
then aliases of
.q /safe/logs/file
and
.q /logs/file
actually indicate the same file.
Additionally, if this option is set,
.i sendmail
refuses to deliver to symbolic links.
.ip SaveFromLine
[f]
Save
Unix-style
.q From
lines at the front of headers.
Normally they are assumed redundant
and discarded.
.ip SendMimeErrors
[j]
If set, send error messages in MIME format
(see RFC2045 and RFC1344 for details).
If disabled,
.i sendmail
will not return the DSN keyword in response to an EHLO
and will not do Delivery Status Notification processing as described in
RFC1891.
.ip ServiceSwitchFile=fIfilenamefP
[no short name]
If your host operating system has a service switch abstraction
(e.g., /etc/nsswitch.conf on Solaris
or /etc/svc.conf on Ultrix and DEC OSF/1)
that service will be consulted and this option is ignored.
Otherwise, this is the name of a file
that provides the list of methods used to implement particular services.
The syntax is a series of lines,
each of which is a sequence of words.
The first word is the service name,
and following words are service types.
The services that
.i sendmail
consults directly are
.q aliases
and
.q hosts.
Service types can be
.q dns ,
.q nis ,
.q nisplus ,
or
.q files
(with the caveat that the appropriate support
must be compiled in
before the service can be referenced).
If ServiceSwitchFile is not specified, it defaults to
/etc/mail/service.switch.
If that file does not exist, the default switch is:
.(b
aliases files
hosts dns nis files
.)b
The default file is
.q /etc/mail/service.switch .
.ip SevenBitInput
[7]
Strip input to seven bits for compatibility with old systems.
This shouldn't be necessary.
.ip SingleLineFromHeader
[no short name]
If set, From: lines that have embedded newlines are unwrapped
onto one line.
This is to get around a botch in Lotus Notes
that apparently cannot understand legally wrapped RFC822 headers.
.ip SingleThreadDelivery
[no short name]
If set, a client machine will never try to open two SMTP connections
to a single server machine at the same time,
even in different processes.
That is, if another
.i sendmail
is already talking to some host a new
.i sendmail
will not open another connection.
This property is of mixed value;
although this reduces the load on the other machine,
it can cause mail to be delayed
(for example, if one
.i sendmail
is delivering a huge message, other
.i sendmail s
won't be able to send even small messages).
Also, it requires another file descriptor
(for the lock file)
per connection, so you may have to reduce the
.b ConnectionCacheSize
option to avoid running out of per-process file descriptors.
Requires the
.b HostStatusDirectory
option.
.ip SmtpGreetingMessage=fImessagefP
[$e macro]
The message printed when the SMTP server starts up.
Defaults to
.q "$j Sendmail $v ready at $b".
.ip StatusFile=fIfilefP
[S]
Log summary statistics in the named
.i file .
If no file name is specified, "statistics" is used.
If not set,
no summary statistics are saved.
This file does not grow in size.
It can be printed using the
.i mailstats (8)
program.
.ip SuperSafe
[s]
Be super-safe when running things,
i.e.,
always instantiate the queue file,
even if you are going to attempt immediate delivery.
.i Sendmail
always instantiates the queue file
before returning control to the client
under any circumstances.
This should really
.i always
be set.
.ip TempFileMode=fImodefP
[F]
The file mode for queue files.
It is interpreted in octal by default.
Defaults to 0600.
.ip Timeout.fItypefP=|fItimeoutfP
[r; subsumes old T option as well]
Set timeout values.
For more information,
see section
." XREF
4.1.
.ip TimeZoneSpec=fItzinfofP
[t]
Set the local time zone info to
.i tzinfo
*- for example,
.q PST8PDT .
Actually, if this is not set,
the TZ environment variable is cleared (so the system default is used);
if set but null, the user's TZ variable is used,
and if set and non-null the TZ variable is set to this value.
.ip TrustedUser=fIuserfP
[no short name]
The
.i user
parameter may be a user name
(looked up in
.i /etc/passwd )
or a numeric user id.
Trusted user for file ownership and starting the daemon. If set, generated
alias databases and the control socket (if configured) will automatically
be owned by this user.
.ip TryNullMXList
[w]
If this system is the
.q best
(that is, lowest preference)
MX for a given host,
its configuration rules should normally detect this situation
and treat that condition specially
by forwarding the mail to a UUCP feed,
treating it as local,
or whatever.
However, in some cases (such as Internet firewalls)
you may want to try to connect directly to that host
as though it had no MX records at all.
Setting this option causes
.i sendmail
to try this.
The downside is that errors in your configuration
are likely to be diagnosed as
.q "host unknown"
or
.q "message timed out"
instead of something more meaningful.
This option is disrecommended.
.ip UnixFromLine=fIfromlinefP
[$l macro]
Defines the format used when
.i sendmail
must add a UNIX-style From_ line
(that is, a line beginning
.q From<space>user ).
Defaults to
.q "From $g $d" .
Don't change this unless your system uses a different UNIX mailbox format
(very unlikely).
.ip UnsafeGroupWrites
[no short name]
If set,
:include: and .forward files that are group writable are considered
.q unsafe ,
that is,
they cannot reference programs or write directly to files.
World writable :include: and .forward files
are always unsafe..
.ip UseErrorsTo
[l]
If there is an
.q Errors-To:
header, send error messages to the addresses listed there.
They normally go to the envelope sender.
Use of this option causes
.i sendmail
to violate RFC 1123.
This option is disrecommended and deprecated.
.ip UserDatabaseSpec=fIudbspecfP
[U]
The user database specification.
.ip Verbose
[v]
Run in verbose mode.
If this is set,
.i sendmail
adjusts options
.b HoldExpensive
(old
.b c )
and
.b DeliveryMode
(old
.b d )
so that all mail is delivered completely
in a single job
so that you can see the entire delivery process.
Option
.b Verbose
should
.i never
be set in the configuration file;
it is intended for command line use only.
.ip XscriptFileBufferSize=fIthresholdfP
[no short name]
Set the
.i threshold ,
in bytes,
before a memory-based
queue transcript file
becomes disk-based.
The default is 4096 bytes.
.lp
All options can be specified on the command line using the
-O or -o flag,
but most will cause
.i sendmail
to relinquish its setuid permissions.
The options that will not cause this are
SevenBitInput [7],
EightBitMode [8],
MinFreeBlocks [b],
CheckpointInterval [C],
DeliveryMode [d],
ErrorMode [e],
IgnoreDots [i],
SendMimeErrors [j],
LogLevel [L],
MeToo [m],
OldStyleHeaders [o],
PrivacyOptions [p],
SuperSafe [s],
Verbose [v],
QueueSortOrder,
MinQueueAge,
DefaultCharSet,
Dial Delay,
NoRecipientAction,
ColonOkInAddr,
MaxQueueRunSize,
SingleLineFromHeader,
and
AllowBogusHELO.
Also, M (define macro) when defining the r or s macros
is also considered
.q safe .
.sh 2 "P *- Precedence Definitions"
.pp
Values for the
.q "Precedence:"
field may be defined using the
.b P
control line.
The syntax of this field is:
.(b
fBPfPfInamefPfB=fPfInumfP
.)b
When the
.i name
is found in a
.q Precedence:
field,
the message class is set to
.i num .
Higher numbers mean higher precedence.
Numbers less than zero
have the special property
that if an error occurs during processing
the body of the message will not be returned;
this is expected to be used for
.q "bulk"
mail such as through mailing lists.
The default precedence is zero.
For example,
our list of precedences is:
.(b
Pfirst-class=0
Pspecial-delivery=100
Plist=-30
Pbulk=-60
Pjunk=-100
.)b
People writing mailing list exploders
are encouraged to use
.q "Precedence: list" .
Older versions of
.i sendmail
(which discarded all error returns for negative precedences)
didn't recognize this name, giving it a default precedence of zero.
This allows list maintainers to see error returns
on both old and new versions of
.i sendmail .
.sh 2 "V *- Configuration Version Level"
.pp
To provide compatibility with old configuration files,
the
.b V
line has been added to define some very basic semantics
of the configuration file.
These are not intended to be long term supports;
rather, they describe compatibility features
which will probably be removed in future releases.
.pp
.b N.B.:
these version
.i levels
have nothing
to do with the version
.i number
on the files.
For example,
as of this writing
version 8 config files
(specifically, 8.10)
used version level 9 configurations.
.pp
.q Old
configuration files are defined as version level one.
Version level two files make the following changes:
.np
Host name canonification ($[ ... $])
appends a dot if the name is recognized;
this gives the config file a way of finding out if anything matched.
(Actually, this just initializes the
.q host
map with the
.q -a.
flag *- you can reset it to anything you prefer
by declaring the map explicitly.)
.np
Default host name extension is consistent throughout processing;
version level one configurations turned off domain extension
(that is, adding the local domain name)
during certain points in processing.
Version level two configurations are expected to include a trailing dot
to indicate that the name is already canonical.
.np
Local names that are not aliases
are passed through a new distinguished ruleset five;
this can be used to append a local relay.
This behavior can be prevented by resolving the local name
with an initial `@'.
That is, something that resolves to a local mailer and a user name of
.q vikki
will be passed through ruleset five,
but a user name of
.q @vikki
will have the `@' stripped,
will not be passed through ruleset five,
but will otherwise be treated the same as the prior example.
The expectation is that this might be used to implement a policy
where mail sent to
.q vikki
was handled by a central hub,
but mail sent to
.q vikki@localhost
was delivered directly.
.pp
Version level three files
allow # initiated comments on all lines.
Exceptions are backslash escaped # marks
and the $# syntax.
.pp
Version level four configurations
are completely equivalent to level three
for historical reasons.
.pp
Version level five configuration files
change the default definition of
.b $w
to be just the first component of the hostname.
.pp
Version level six configuration files
change many of the local processing options
(such as aliasing and matching the beginning of the address for
`|' characters)
to be mailer flags;
this allows fine-grained control over the special local processing.
Level six configuration files may also use long option names.
The
.b ColonOkInAddr
option (to allow colons in the local-part of addresses)
defaults
.b on
for lower numbered configuration files;
the configuration file requires some additional intelligence
to properly handle the RFC 822 group construct.
.pp
Version level seven configuration files
used new option names to replace old macros
(c
.b $e
became
.b SmtpGreetingMessage ,
.b $l
became
.b UnixFromLine ,
and
.b $o
became
.b OperatorChars .
Also, prior to version seven,
the
.b F=q
flag (use 250 instead of 252 return value for
.sm "SMTP VRFY"
commands)
was assumed.
.pp
Version level eight configuration files allow
.b $#
on the left hand side of ruleset lines.
.pp
Version level nine configuration files allow
parentheses in rulesets, i.e. they are not treated
as comments and hence removed.
.pp
The
.b V
line may have an optional
.b / c
.i vendor
to indicate that this configuration file uses modifications
specific to a particular vendor**.
.(f
**And of course, vendors are encouraged to add themselves
to the list of recognized vendors by editing the routine
.i setvendor
in
.i conf.c .
Please send e-mail to sendmail@Sendmail.ORG
to register your vendor dialect.
.)f
You may use
.q /Berkeley
to emphasize that this configuration file
uses the Berkeley dialect of
.i sendmail .
.sh 2 "K *- Key File Declaration"
.pp
Special maps can be defined using the line:
.(b
Kmapname mapclass arguments
.)b
The
.i mapname
is the handle by which this map is referenced in the rewriting rules.
The
.i mapclass
is the name of a type of map;
these are compiled in to
.i sendmail .
The
.i arguments
are interpreted depending on the class;
typically,
there would be a single argument naming the file containing the map.
.pp
Maps are referenced using the syntax:
.(b
$( fImapfP fIkeyfP $@ fIargumentsfP $: fIdefaultfP $)
.)b
where either or both of the
.i arguments
or
.i default
portion may be omitted.
The
.i "$@ arguments"
may appear more than once.
The indicated
.i key
and
.i arguments
are passed to the appropriate mapping function.
If it returns a value, it replaces the input.
If it does not return a value and the
.i default
is specified, the
.i default
replaces the input.
Otherwise, the input is unchanged.
.pp
The
.i arguments
are passed to the map for arbitrary use.
Most map classes can interpolate these arguments
into their values using the syntax
.q %fInfP
(where
.i n
is a digit)
to indicate the corresponding
.i argument .
Argument
.q %0
indicates the database key.
For example, the rule
.(b
.ta 1.5i
R$- ! $+ $: $(uucp $1 $@ $2 $: %1 @ %0 . UUCP $)
.)b
Looks up the UUCP name in a (user defined) UUCP map;
if not found it turns it into
.q &.UUCP
form.
The database might contain records like:
.(b
decvax %1@%0.DEC.COM
research %1@%0.ATT.COM
.)b
Note that
.i default
clauses never do this mapping.
.pp
The built in map with both name and class
.q host
is the host name canonicalization lookup.
Thus,
the syntax:
.(b
$(host fIhostnamefP$)
.)b
is equivalent to:
.(b
$[fIhostnamefP$]
.)b
.pp
There are many defined classes.
.ip dbm
Database lookups using the ndbm(3) library.
.i Sendmail
must be compiled with
.b NDBM
defined.
.ip btree
Database lookups using the btree interface to the Berkeley DB
library.
.i Sendmail
must be compiled with
.b NEWDB
defined.
.ip hash
Database lookups using the hash interface to the Berkeley DB
library.
.i Sendmail
must be compiled with
.b NEWDB
defined.
.ip nis
NIS lookups.
.i Sendmail
must be compiled with
.b NIS
defined.
.ip nisplus
NIS+ lookups.
.i Sendmail
must be compiled with
.b NISPLUS
defined.
The argument is the name of the table to use for lookups,
and the
.b -k
and
.b -v
flags may be used to set the key and value columns respectively.
.ip hesiod
Hesiod lookups.
.i Sendmail
must be compiled with
.b HESIOD
defined.
.ip ldap
LDAP X500 directory lookups.
.i Sendmail
must be compiled with
.b LDAPMAP
defined.
The map supports most of the standard arguments
and most of the command line arguments of the
.i ldapsearch
program.
Note that,
by default,
if a single query matches multiple values,
only the first value will be returned
unless the
.b -z
(value separator)
map flag is set.
Also, the
.b -1
map flag will treat a multiple value return
as if there were no matches.
.ip netinfo
NeXT NetInfo lookups.
.i Sendmail
must be compiled with
.b NETINFO
defined.
.ip text
Text file lookups.
The format of the text file is defined by the
.b -k
(key field number),
.b -v
(value field number),
and
.b -z
(field delimiter)
flags.
.ip ph
PH query map.
Contributed and supported by
Mark Roth, roth@uiuc.edu.
For more information,
consult the web site
.q http://www-wsg.cso.uiuc.edu/sendmail/sendmail-phmap/ .
.ip nsd
nsd map for IRIX 6.5 and later.
Contributed and supported by Bob Mende of SGI,
mende@sgi.com.
.ip stab
Internal symbol table lookups.
Used internally for aliasing.
.ip implicit
Really should be called
.q alias
(em this is used to get the default lookups
for alias files,
and is the default if no class is specified for alias files.
.ip user
Looks up users using
.i getpwnam (3).
The
.b -v
flag can be used to specify the name of the field to return
(although this is normally used only to check the existence
of a user).
.ip host
Canonifies host domain names.
Given a host name it calls the name server
to find the canonical name for that host.
.ip bestmx
Returns the best MX record for a host name given as the key.
The current machine is always preferred *-
that is, if the current machine is one of the hosts listed as a
lowest-preference MX record, then it will be guaranteed to be returned.
This can be used to find out if this machine is the target for an MX record,
and mail can be accepted on that basis.
If the
.b -z
flag is given, then all MX names are returned,
separated by the given delimiter.
.ip sequence
The arguments on the `K' line are a list of maps;
the resulting map searches the argument maps in order
until it finds a match for the indicated key.
For example, if the key definition is:
.(b
Kmap1 ...
Kmap2 ...
Kseqmap sequence map1 map2
.)b
then a lookup against
.q seqmap
first does a lookup in map1.
If that is found, it returns immediately.
Otherwise, the same key is used for map2.
.ip syslog
the key is logged via
.i syslogd |(8).
The lookup returns the empty string.
.ip switch
Much like the
.q sequence
map except that the order of maps is determined by the service switch.
The argument is the name of the service to be looked up;
the values from the service switch are appended to the map name
to create new map names.
For example, consider the key definition:
.(b
Kali switch aliases
.)b
together with the service switch entry:
.(b
aliases nis files
.)b
This causes a query against the map
.q ali
to search maps named
.q ali.nis
and
.q ali.files
in that order.
.ip dequote
Strip double quotes (") from a name.
It does not strip backslashes,
and will not strip quotes if the resulting string
would contain unscannable syntax
(that is, basic errors like unbalanced angle brackets;
more sophisticated errors such as unknown hosts are not checked).
The intent is for use when trying to accept mail from systems such as
DECnet
that routinely quote odd syntax such as
.(b
"49ers::ubell"
.)b
A typical usage is probably something like:
.(b
Kdequote dequote
&...
R$- $: $(dequote $1 $)
R$- $+ $: $>3 $1 $2
.)b
Care must be taken to prevent unexpected results;
for example,
.(b
"|someprogram < input > output"
.)b
will have quotes stripped,
but the result is probably not what you had in mind.
Fortunately these cases are rare.
.ip regex
The map definition on the
.b K
line contains a regular expression.
Any key input is compared to that expression using the
POSIX regular expressions routines regcomp(), regerr(), and regexec().
Refer to the documentation for those routines for more information
about the regular expression matching.
No rewriting of the key is done if the
.b -m
flag is used. Without it, the key is discarded or if
.b -s
if used, it is substituted by the substring matches, delimited by
.b $|
or the string specified with the the
.b -d
flag. The flags available for the map are
.(b
-n not
-f case sensitive
-b basic regular expressions
(default is extended)
-s substring match
-d set the delimiter used for -s
-a append string to key
-m match only, do not
replace/discard value
-D perform no lookup in deferred delivery mode.
.)b
The
.b -s
flag can include an optional parameter which can be used
to select the substrings in the result of the lookup. For example,
.(b
-s1,3,4
.)b
.ip program
The arguments on the
.b K
line are the pathname to a program and any initial parameters to be passed.
When the map is called,
the key is added to the initial parameters
and the program is invoked
as the default user/group id.
The first line of standard output is returned as the value of the lookup.
This has many potential security problems,
and has terrible performance;
it should be used only when absolutely necessary.
.ip macro
Set or clear a macro value.
To set a macro,
pass the value as the first argument in the map lookup.
To clear a macro,
do not pass an argument in the map lookup.
The map always returns the empty string.
Example of typical usage include:
.(b
Kstorage macro
&...
# set macro ${MyMacro} to the ruleset match
R$+ $: $(storage {MyMacro} $@ $1 $) $1
# set macro ${MyMacro} to an empty string
R$* $: $(storage {MyMacro} $@ $) $1
# clear macro ${MyMacro}
R$- $: $(storage {MyMacro} $) $1
.)b
.ip arith
Perform simple arithmetic operations.
The operation is given as key, currently +, -, *, /,
l (for less than), and = are supported.
The two operands are given as arguments.
The lookup returns the result of the computation,
i.e.
.sm TRUE
or
.sm FALSE
for comparisons, integer values otherwise.
All options which are possible for maps are ignored.
A simple example is:
.(b
Kcomp arith
&...
Scheck_etrn
R$* $: $(comp l $@ $&{load_avg} $@ 7 $) $1
RFALSE $# error &...
.)b
.pp
Most of these accept as arguments the same optional flags
and a filename
(or a mapname for NIS;
the filename is the root of the database path,
so that
.q .db
or some other extension appropriate for the database type
will be added to get the actual database name).
Known flags are:
.ip "-o"
Indicates that this map is optional *- that is,
if it cannot be opened,
no error is produced,
and
.i sendmail
will behave as if the map existed but was empty.
.ip "-N, -O"
If neither
.b -N
or
.b -O
are specified,
.i sendmail
uses an adaptive algorithm to decide whether or not to look for null bytes
on the end of keys.
It starts by trying both;
if it finds any key with a null byte it never tries again without a null byte
and vice versa.
If
.b -N
is specified it never tries without a null byte and
if
.b -O
is specified it never tries with a null byte.
Setting one of
these can speed matches but are never necessary.
If both
.b -N
and
.b -O
are specified,
.i sendmail
will never try any matches at all (em
that is, everything will appear to fail.
.ip "-afIxfP"
Append the string
.i x
on successful matches.
For example, the default
.i host
map appends a dot on successful matches.
.ip "-TfIxfP"
Append the string
.i x
on temporary failures.
For example,
.i x
would be appended if a DNS lookup returned
.q "server failed"
or an NIS lookup could not locate a server.
See also the
.b -t
flag.
.ip "-f"
Do not fold upper to lower case before looking up the key.
.ip "-m"
Match only (without replacing the value).
If you only care about the existence of a key and not the value
(as you might when searching the NIS map
.q hosts.byname
for example),
this flag prevents the map from substituting the value.
However,
The -a argument is still appended on a match,
and the default is still taken if the match fails.
.ip "-kfIkeycolfP"
The key column name (for NIS+) or number
(for text lookups).
For LDAP maps this is an LDAP filter string
in which %s is replaced with the literal contents of the lookup key
and %0 is replaced with the LDAP escaped contents of the lookup key
according to RFC2254.
.ip "-vfIvalcolfP"
The value column name (for NIS+) or number
(for text lookups).
For LDAP maps this is the name of one or more
attributes to be returned;
multiple attributes can be separated by commas.
If not specified, all attributes found in the match
will be returned.
.ip "-zfIdelimfP"
The column delimiter (for text lookups).
It can be a single character or one of the special strings
.q |en
or
.q |et
to indicate newline or tab respectively.
If omitted entirely,
the column separator is any sequence of whitespace.
For LDAP maps this is the separator character
to combine multiple values
into a single return string.
If not set,
the LDAP lookup will only return the first match found.
.ip "-t"
Normally, when a map attempts to do a lookup
and the server fails
(e.g.,
.i sendmail
couldn't contact any name server;
this is
.i not
the same as an entry not being found in the map),
the message being processed is queued for future processing.
The
.b -t
flag turns off this behavior,
letting the temporary failure (server down)
act as though it were a permanent failure (entry not found).
It is particularly useful for DNS lookups,
where someone else's misconfigured name server can cause problems
on your machine.
However, care must be taken to ensure that you don't bounce mail
that would be resolved correctly if you tried again.
A common strategy is to forward such mail
to another, possibly better connected, mail server.
.ip "-D"
Perform no lookup in deferred delivery mode.
This flag is set by default for the
.i host
map.
.ip "-SfIspacesubfP
The character to use to replace space characters
after a successful map lookup (esp. useful for regex
and syslog maps).
.ip "-sfIspacesubfP
For the dequote map only,
the character to use to replace space characters
after a successful dequote.
.ip "-q"
Don't dequote the key before lookup.
.ip "-LfIlevelfP
For the syslog map only, it specifies the level
to use for the syslog call.
.ip "-A"
When rebuilding an alias file,
the
.b -A
flag causes duplicate entries in the text version
to be merged.
For example, two entries:
.(b
list: user1, user2
list: user3
.)b
would be treated as though it were the single entry
.(b
list: user1, user2, user3
.)b
in the presence of the
.b -A
flag.
.pp
The following additional flags are present in the ldap map only:
.ip "-R"
Do not auto chase referrals. sendmail must be compiled with
.b -DLDAP_REFERRALS
to use this flag.
.ip "-n"
Retrieve attribute names only.
.ip "-rfIdereffP"
Set the alias dereference option to one of never, always, search, or find.
.ip "-sfIscopefP"
Set search scope to one of base, one (one level), or sub (subtree).
.ip "-hfIhostfP"
LDAP server hostname.
.ip "-bfIbasefP"
LDAP search base.
.ip "-pfIportfP"
LDAP service port.
.ip "-lfItimelimitfP"
Time limit for LDAP queries.
.ip "-ZfIsizelimitfP"
Size (number of matches) limit for LDAP queries.
.ip "-dfIdistinguished_namefP"
The distinguished name to use to login to the LDAP server.
.ip "-MfImethodfP"
The method to authenticate to the LDAP server.
Should be one of
.b LDAP_AUTH_NONE ,
.b LDAP_AUTH_SIMPLE ,
or
.b LDAP_AUTH_KRBV4 .
.ip "-PfIpasswordfilefP"
The file containing the secret key for the
.b LDAP_AUTH_SIMPLE
authentication method
or the name of the Kerberos ticket file for
.b LDAP_AUTH_KRBV4 .
.ip "-1"
Force LDAP searches to only succeed if a single match is found.
If multiple values are found,
the search is treated as if no match was found.
.pp
The
.i dbm
map appends the strings
.q &.pag
and
.q &.dir
to the given filename;
the
.i hash
and
.i btree
maps append
.q &.db .
For example, the map specification
.(b
Kuucp dbm -o -N /etc/mail/uucpmap
.)b
specifies an optional map named
.q uucp
of class
.q dbm ;
it always has null bytes at the end of every string,
and the data is located in
/etc/mail/uucpmap.{dir,pag}.
.pp
The program
.i makemap (8)
can be used to build any of the three database-oriented maps.
It takes the following flags:
.ip -f
Do not fold upper to lower case in the map.
.ip -N
Include null bytes in keys.
.ip -o
Append to an existing (old) file.
.ip -r
Allow replacement of existing keys;
normally, re-inserting an existing key is an error.
.ip -v
Print what is happening.
.lp
The
.i sendmail
daemon does not have to be restarted to read the new maps
as long as you change them in place;
file locking is used so that the maps won't be read
while they are being updated.
.pp
New classes can be added in the routine
.b setupmaps
in file
.b conf.c .
.sh 2 "The User Database"
.pp
If you have a version of
.i sendmail
with the user database package
compiled in,
the handling of sender and recipient addresses
is modified.
.pp
The location of this database is controlled with the
.b UserDatabaseSpec
option.
.sh 3 "Structure of the user database"
.pp
The database is a sorted (BTree-based) structure.
User records are stored with the key:
.(b
fIuser-namefPfB:fPfIfield-namefP
.)b
The sorted database format ensures that user records are clustered together.
Meta-information is always stored with a leading colon.
.pp
Field names define both the syntax and semantics of the value.
Defined fields include:
.nr ii 1i
.ip maildrop
The delivery address for this user.
There may be multiple values of this record.
In particular,
mailing lists will have one
.i maildrop
record for each user on the list.
.ip "mailname"
The outgoing mailname for this user.
For each outgoing name,
there should be an appropriate
.i maildrop
record for that name to allow return mail.
See also
.i :default:mailname .
.ip mailsender
Changes any mail sent to this address to have the indicated envelope sender.
This is intended for mailing lists,
and will normally be the name of an appropriate -request address.
It is very similar to the owner-c
.i list
syntax in the alias file.
.ip fullname
The full name of the user.
.ip office-address
The office address for this user.
.ip office-phone
The office phone number for this user.
.ip office-fax
The office FAX number for this user.
.ip home-address
The home address for this user.
.ip home-phone
The home phone number for this user.
.ip home-fax
The home FAX number for this user.
.ip project
A (short) description of the project this person is affiliated with.
In the University this is often just the name of their graduate advisor.
.ip plan
A pointer to a file from which plan information can be gathered.
.pp
As of this writing,
only a few of these fields are actually being used by
.i sendmail :
.i maildrop
and
.i mailname .
A
.i finger
program that uses the other fields is planned.
.sh 3 "User database semantics"
.pp
When the rewriting rules submit an address to the local mailer,
the user name is passed through the alias file.
If no alias is found (or if the alias points back to the same address),
the name (with
.q :maildrop
appended)
is then used as a key in the user database.
If no match occurs (or if the maildrop points at the same address),
forwarding is tried.
.pp
If the first token of the user name returned by ruleset 0
is an
.q @
sign, the user database lookup is skipped.
The intent is that the user database will act as a set of defaults
for a cluster (in our case, the Computer Science Division);
mail sent to a specific machine should ignore these defaults.
.pp
When mail is sent,
the name of the sending user is looked up in the database.
If that user has a
.q mailname
record,
the value of that record is used as their outgoing name.
For example, I might have a record:
.(b
eric:mailname Eric.Allman@CS.Berkeley.EDU
.)b
This would cause my outgoing mail to be sent as Eric.Allman.
.pp
If a
.q maildrop
is found for the user,
but no corresponding
.q mailname
record exists,
the record
.q :default:mailname
is consulted.
If present, this is the name of a host to override the local host.
For example, in our case we would set it to
.q CS.Berkeley.EDU .
The effect is that anyone known in the database
gets their outgoing mail stamped as
.q user@CS.Berkeley.EDU ,
but people not listed in the database use the local hostname.
.sh 3 "Creating the database**"
.(f
**These instructions are known to be incomplete.
A future version of the user database is planned
including things such as finger service *- and good documentation.
.)f
.pp
The user database is built from a text file
using the
.i makemap
utility
(in the distribution in the makemap subdirectory).
The text file is a series of lines corresponding to userdb records;
each line has a key and a value separated by white space.
The key is always in the format described above *-
for example:
.(b
eric:maildrop
.)b
This file is normally installed in a system directory;
for example, it might be called
.i /etc/mail/userdb .
To make the database version of the map, run the program:
.(b
makemap btree /etc/mail/userdb < /etc/mail/userdb
.)b
Then create a config file that uses this.
For example, using the V8 M4 configuration, include the
following line in your .mc file:
.(b
define(`confUSERDB_SPEC', /etc/mail/userdb.db)
.)b
.sh 1 "OTHER CONFIGURATION"
.pp
There are some configuration changes that can be made by
recompiling
.i sendmail .
This section describes what changes can be made
and what has to be modified to make them.
In most cases this should be unnecessary
unless you are porting
.i sendmail
to a new environment.
.sh 2 "Parameters in devtools/OS/$oscf"
.pp
These parameters are intended to describe the compilation environment,
not site policy,
and should normally be defined in the operating system
configuration file.
.b "This section needs a complete rewrite."
.ip NDBM
If set,
the new version of the DBM library
that allows multiple databases will be used.
If neither NDBM nor NEWDB are set,
a much less efficient method of alias lookup is used.
.ip NEWDB
If set, use the new database package from Berkeley (from 4.4BSD).
This package is substantially faster than DBM or NDBM.
If NEWDB and NDBM are both set,
.i sendmail
will read DBM files,
but will create and use NEWDB files.
.ip NIS
Include support for NIS.
If set together with
.i both
NEWDB and NDBM,
.i sendmail
will create both DBM and NEWDB files if and only if
an alias file includes the substring
.q /yp/
in the name.
This is intended for compatibility with Sun Microsystems'
.i mkalias
program used on YP masters.
.ip NISPLUS
Compile in support for NIS+.
.ip NETINFO
Compile in support for NetInfo (NeXT stations).
.ip LDAPMAP
Compile in support for LDAP X500 queries.
Requires libldap and liblber
from the Umich LDAP 3.2 or 3.3 release
or equivalent libraries for other LDAP libraries
such as OpenLDAP.
.ip HESIOD
Compile in support for Hesiod.
.ip MAP_NSD
Compile in support for IRIX NSD lookups.
.ip MAP_REGEX
Compile in support for regular expression matching.
.ip PH_MAP
Compile in support for ph lookups.
.ip SASL
Compile in support for SASL,
a required component for SMTP Authentication support.
.ip TCPWRAPPERS
Compile in support for TCP Wrappers.
.ip _PATH_SENDMAILCF
The pathname of the sendmail.cf file.
.ip _PATH_SENDMAILPID
The pathname of the sendmail.pid file.
.pp
There are also several compilation flags to indicate the environment
such as
.q _AIX3
and
.q _SCO_unix_ .
See the sendmail/README
file for the latest scoop on these flags.
.sh 2 "Parameters in sendmail/conf.h"
.pp
Parameters and compilation options
are defined in conf.h.
Most of these need not normally be tweaked;
common parameters are all in sendmail.cf.
However, the sizes of certain primitive vectors, etc.,
are included in this file.
The numbers following the parameters
are their default value.
.pp
This document is not the best source of information
for compilation flags in conf.h (em
see sendmail/README or sendmail/conf.h itself.
.nr ii 1.2i
.ip "MAXLINE [2048]"
The maximum line length of any input line.
If message lines exceed this length
they will still be processed correctly;
however, header lines,
configuration file lines,
alias lines,
etc.,
must fit within this limit.
.ip "MAXNAME [256]"
The maximum length of any name,
such as a host or a user name.
.ip "MAXPV [256]"
The maximum number of parameters to any mailer.
This limits the number of recipients that may be passed in one transaction.
It can be set to any arbitrary number above about 10,
since
.i sendmail
will break up a delivery into smaller batches as needed.
A higher number may reduce load on your system, however.
.ip "MAXATOM [1000]"
The maximum number of atoms
(tokens)
in a single address.
For example,
the address
.q "eric@CS.Berkeley.EDU"
is seven atoms.
.ip "MAXMAILERS [25]"
The maximum number of mailers that may be defined
in the configuration file.
.ip "MAXRWSETS [200]"
The maximum number of rewriting sets
that may be defined.
The first half of these are reserved for numeric specification
(e.g., ``S92''),
while the upper half are reserved for auto-numbering
(e.g., ``Sfoo'').
Thus, with a value of 200 an attempt to use ``S99'' will succeed,
but ``S100'' will fail.
.ip "MAXPRIORITIES [25]"
The maximum number of values for the
.q Precedence:
field that may be defined
(using the
.b P
line in sendmail.cf).
.ip "MAXUSERENVIRON [100]"
The maximum number of items in the user environment
that will be passed to subordinate mailers.
.ip "MAXMXHOSTS [100]"
The maximum number of MX records we will accept for any single host.
.ip "MAXALIASDB [12]"
The maximum number of alias databases that can be open at any time.
Note that there may also be an open file limit.
.ip "MAXMAPSTACK [12]"
The maximum number of maps that may be "stacked" in a
.b sequence
class map.
.ip "MAXMIMEARGS [20]"
The maximum number of arguments in a MIME Content-Type: header;
additional arguments will be ignored.
.ip "MAXMIMENESTING [20]"
The maximum depth to which MIME messages may be nested
(that is, nested Message or Multipart documents;
this does not limit the number of components in a single Multipart document).
.ip "MAXDAEMONS [10]"
The maximum number of sockets sendmail will open for accepting connections
on different ports.
.ip "MAXMACNAMELEN [25]"
The maximum length of a macro name.
.lp
A number of other compilation options exist.
These specify whether or not specific code should be compiled in.
Ones marked with (dg
are 0/1 valued.
.nr ii 1.2i
.ip NETINET(dg
If set,
support for Internet protocol networking is compiled in.
Previous versions of
.i sendmail
referred to this as
.sm DAEMON ;
this old usage is now incorrect.
Defaults on;
turn it off in the Makefile
if your system doesn't support the Internet protocols.
.ip NETINET6(dg
If set,
support for IPv6 networking is compiled in.
.ip NETISO(dg
If set,
support for ISO protocol networking is compiled in
(it may be appropriate to #define this in the Makefile instead of conf.h).
.ip NETUNIX(dg
If set,
support for UNIX domain sockets is compiled in.
This is used for control socket support.
.ip LOG
If set,
the
.i syslog
routine in use at some sites is used.
This makes an informational log record
for each message processed,
and makes a higher priority log record
for internal system errors.
.b "STRONGLY RECOMMENDED"
(em if you want no logging, turn it off in the configuration file.
.ip MATCHGECOS(dg
Compile in the code to do ``fuzzy matching'' on the GECOS field
in /etc/passwd.
This also requires that the
.b MatchGECOS
option be turned on.
.ip NAMED_BIND(dg
Compile in code to use the
Berkeley Internet Name Domain (BIND) server
to resolve TCP/IP host names.
.ip NOTUNIX
If you are using a non-UNIX mail format,
you can set this flag to turn off special processing
of UNIX-style
.q "From "
lines.
.ip QUEUE(dg
This flag should be set to compile in the queueing code.
If this is not set,
mailers must accept the mail immediately
or it will be returned to the sender.
.ip SMTP(dg
If set,
the code to handle user and server SMTP will be compiled in.
This is only necessary if your machine has some mailer
that speaks SMTP
(this means most machines everywhere).
.ip USERDB(dg
Include the
.b experimental
Berkeley user information database package.
This adds a new level of local name expansion
between aliasing and forwarding.
It also uses the NEWDB package.
This may change in future releases.
.lp
The following options are normally turned on
in per-operating-system clauses in conf.h.
.ip IDENTPROTO(dg
Compile in the IDENT protocol as defined in RFC 1413.
This defaults on for all systems except Ultrix,
which apparently has the interesting
.q feature
that when it receives a
.q "host unreachable"
message it closes all open connections to that host.
Since some firewall gateways send this error code
when you access an unauthorized port (such as 113, used by IDENT),
Ultrix cannot receive email from such hosts.
.ip SYSTEM5
Set all of the compilation parameters appropriate for System V.
.ip HASFLOCK(dg
Use Berkeley-style
.b flock
instead of System V
.b lockf
to do file locking.
Due to the highly unusual semantics of locks
across forks in
.b lockf ,
this should always be used if at all possible.
.ip HASINITGROUPS
Set this if your system has the
.i initgroups()
call
(if you have multiple group support).
This is the default if SYSTEM5 is
.i not
defined or if you are on HPUX.
.ip HASUNAME
Set this if you have the
.i uname (2)
system call (or corresponding library routine).
Set by default if
SYSTEM5
is set.
.ip HASGETDTABLESIZE
Set this if you have the
.i getdtablesize (2)
system call.
.ip HASWAITPID
Set this if you have the
.i haswaitpid (2)
system call.
.ip FAST_PID_RECYCLE
Set this if your system can possibly
reuse the same pid in the same second of time.
.ip SFS_TYPE
The mechanism that can be used to get file system capacity information.
The values can be one of
SFS_USTAT (use the ustat(2) syscall),
SFS_4ARGS (use the four argument statfs(2) syscall),
SFS_VFS (use the two argument statfs(2) syscall including <sys/vfs.h>),
SFS_MOUNT (use the two argument statfs(2) syscall including <sys/mount.h>),
SFS_STATFS (use the two argument statfs(2) syscall including <sys/statfs.h>),
SFS_STATVFS (use the two argument statfs(2) syscall including <sys/statvfs.h>),
or
SFS_NONE (no way to get this information).
.ip LA_TYPE
The load average type.
Details are described below.
.lp
The are several built-in ways of computing the load average.
.i Sendmail
tries to auto-configure them based on imperfect guesses;
you can select one using the
.i cc
option
.b -DLA_TYPE= c
.i type ,
where
.i type
is:
.ip LA_INT
The kernel stores the load average in the kernel as an array of long integers.
The actual values are scaled by a factor FSCALE
(default 256).
.ip LA_SHORT
The kernel stores the load average in the kernel as an array of short integers.
The actual values are scaled by a factor FSCALE
(default 256).
.ip LA_FLOAT
The kernel stores the load average in the kernel as an array of
double precision floats.
.ip LA_MACH
Use MACH-style load averages.
.ip LA_SUBR
Call the
.i getloadavg
routine to get the load average as an array of doubles.
.ip LA_ZERO
Always return zero as the load average.
This is the fallback case.
.lp
If type
.sm LA_INT ,
.sm LA_SHORT ,
or
.sm LA_FLOAT
is specified,
you may also need to specify
.sm _PATH_UNIX
(the path to your system binary)
and
.sm LA_AVENRUN
(the name of the variable containing the load average in the kernel;
usually
.q _avenrun
or
.q avenrun ).
.sh 2 "Configuration in sendmail/conf.c"
.pp
The following changes can be made in conf.c.
.sh 3 "Built-in Header Semantics"
.pp
Not all header semantics are defined in the configuration file.
Header lines that should only be included by certain mailers
(as well as other more obscure semantics)
must be specified in the
.i HdrInfo
table in
.i conf.c .
This table contains the header name
(which should be in all lower case)
and a set of header control flags (described below),
The flags are:
.ip H_ACHECK
Normally when the check is made to see if a header line is compatible
with a mailer,
.i sendmail
will not delete an existing line.
If this flag is set,
.i sendmail
will delete
even existing header lines.
That is,
if this bit is set and the mailer does not have flag bits set
that intersect with the required mailer flags
in the header definition in
sendmail.cf,
the header line is
.i always
deleted.
.ip H_EOH
If this header field is set,
treat it like a blank line,
i.e.,
it will signal the end of the header
and the beginning of the message text.
.ip H_FORCE
Add this header entry
even if one existed in the message before.
If a header entry does not have this bit set,
.i sendmail
will not add another header line if a header line
of this name already existed.
This would normally be used to stamp the message
by everyone who handled it.
.ip H_TRACE
If set,
this is a timestamp
(trace)
field.
If the number of trace fields in a message
exceeds a preset amount
the message is returned
on the assumption that it has an aliasing loop.
.ip H_RCPT
If set,
this field contains recipient addresses.
This is used by the
.b -t
flag to determine who to send to
when it is collecting recipients from the message.
.ip H_FROM
This flag indicates that this field
specifies a sender.
The order of these fields in the
.i HdrInfo
table specifies
.i sendmail 's
preference
for which field to return error messages to.
.ip H_ERRORSTO
Addresses in this header should receive error messages.
.ip H_CTE
This header is a Content-Transfer-Encoding header.
.ip H_CTYPE
This header is a Content-Type header.
.ip H_STRIPVAL
Strip the value from the header (for Bcc:).
.nr ii 5n
.lp
Let's look at a sample
.i HdrInfo
specification:
.(b
.ta 4n +w'"content-transfer-encoding", 'u
struct hdrinfo HdrInfo[] =
&{
/* originator fields, most to least significant */
"resent-sender", H_FROM,
"resent-from", H_FROM,
"sender", H_FROM,
"from", H_FROM,
"full-name", H_ACHECK,
"errors-to", H_FROM^|^H_ERRORSTO,
/* destination fields */
"to", H_RCPT,
"resent-to", H_RCPT,
"cc", H_RCPT,
"bcc", H_RCPT^|^H_STRIPVAL,
/* message identification and control */
"message", H_EOH,
"text", H_EOH,
/* trace fields */
"received", H_TRACE^|^H_FORCE,
/* miscellaneous fields */
"content-transfer-encoding", H_CTE,
"content-type", H_CTYPE,
NULL, 0,
};
.)b
This structure indicates that the
.q To: ,
.q Resent-To: ,
and
.q Cc:
fields
all specify recipient addresses.
Any
.q Full-Name:
field will be deleted unless the required mailer flag
(indicated in the configuration file)
is specified.
The
.q Message:
and
.q Text:
fields will terminate the header;
these are used by random dissenters around the network world.
The
.q Received:
field will always be added,
and can be used to trace messages.
.pp
There are a number of important points here.
First,
header fields are not added automatically just because they are in the
.i HdrInfo
structure;
they must be specified in the configuration file
in order to be added to the message.
Any header fields mentioned in the configuration file but not
mentioned in the
.i HdrInfo
structure have default processing performed;
that is,
they are added unless they were in the message already.
Second,
the
.i HdrInfo
structure only specifies cliched processing;
certain headers are processed specially by ad hoc code
regardless of the status specified in
.i HdrInfo .
For example,
the
.q Sender:
and
.q From:
fields are always scanned on ARPANET mail
to determine the sender**;
.(f
**Actually, this is no longer true in SMTP;
this information is contained in the envelope.
The older ARPANET protocols did not completely distinguish
envelope from header.
.)f
this is used to perform the
.q "return to sender"
function.
The
.q "From:"
and
.q "Full-Name:"
fields are used to determine the full name of the sender
if possible;
this is stored in the macro
.b $x
and used in a number of ways.
.sh 3 "Restricting Use of Email"
.pp
If it is necessary to restrict mail through a relay,
the
.i checkcompat
routine can be modified.
This routine is called for every recipient address.
It returns an exit status
indicating the status of the message.
The status
.sm EX_OK
accepts the address,
.sm EX_TEMPFAIL
queues the message for a later try,
and other values
(commonly
.sm EX_UNAVAILABLE )
reject the message.
It is up to
.i checkcompat
to print an error message
(using
.i usrerr )
if the message is rejected.
For example,
.i checkcompat
could read:
.(b
.re
.sz -1
.ta 4n +4n +4n +4n +4n +4n +4n
int
checkcompat(to, e)
register ADDRESS *to;
register ENVELOPE *e;
&{
register STAB *s;
s = stab("private", ST_MAILER, ST_FIND);
if (s != NULL && e->e_from.q_mailer != LocalMailer &&
to->q_mailer == s->s_mailer)
{
usrerr("No private net mail allowed through this machine");
return (EX_UNAVAILABLE);
}
if (MsgSize > 50000 && bitnset(M_LOCALMAILER, to->q_mailer))
{
usrerr("Message too large for non-local delivery");
e->e_flags |= EF_NORETURN;
return (EX_UNAVAILABLE);
}
return (EX_OK);
}
.sz
.)b
This would reject messages greater than 50000 bytes
unless they were local.
The
.i EF_NORETURN
flag can be set in
.i e(->e_flags
to suppress the return of the actual body
of the message in the error return.
The actual use of this routine is highly dependent on the
implementation,
and use should be limited.
.sh 3 "New Database Map Classes"
.pp
New key maps can be added by creating a class initialization function
and a lookup function.
These are then added to the routine
.i setupmaps.
.pp
The initialization function is called as
.(b
fIxxxfP_map_init(MAP *map, char *args)
.)b
The
.i map
is an internal data structure.
The
.i args
is a pointer to the portion of the configuration file line
following the map class name;
flags and filenames can be extracted from this line.
The initialization function must return
.sm TRUE
if it successfully opened the map,
.sm FALSE
otherwise.
.pp
The lookup function is called as
.(b
fIxxxfP_map_lookup(MAP *map, char buf[], char **av, int *statp)
.)b
The
.i map
defines the map internally.
The
.i buf
has the input key.
This may be (and often is) used destructively.
The
.i av
is a list of arguments passed in from the rewrite line.
The lookup function should return a pointer to the new value.
If the map lookup fails,
.i *statp
should be set to an exit status code;
in particular, it should be set to
.sm EX_TEMPFAIL
if recovery is to be attempted by the higher level code.
.sh 3 "Queueing Function"
.pp
The routine
.i shouldqueue
is called to decide if a message should be queued
or processed immediately.
Typically this compares the message priority to the current load average.
The default definition is:
.(b
bool
shouldqueue(pri, ctime)
long pri;
time_t ctime;
{
if (CurrentLA < QueueLA)
return (FALSE);
return (pri > (QueueFactor / (CurrentLA - QueueLA + 1)));
}
.)b
If the current load average
(global variable
.i CurrentLA ,
which is set before this function is called)
is less than the low threshold load average
(option
.b x ,
variable
.i QueueLA ),
.i shouldqueue
returns
.sm FALSE
immediately
(that is, it should
.i not
queue).
If the current load average exceeds the high threshold load average
(option
.b X ,
variable
.i RefuseLA ),
.i shouldqueue
returns
.sm TRUE
immediately.
Otherwise, it computes the function based on the message priority,
the queue factor
(option
.b q ,
global variable
.i QueueFactor ),
and the current and threshold load averages.
.pp
An implementation wishing to take the actual age of the message into account
can also use the
.i ctime
parameter,
which is the time that the message was first submitted to
.i sendmail .
Note that the
.i pri
parameter is already weighted
by the number of times the message has been tried
(although this tends to lower the priority of the message with time);
the expectation is that the
.i ctime
would be used as an
.q "escape clause"
to ensure that messages are eventually processed.
.sh 3 "Refusing Incoming SMTP Connections"
.pp
The function
.i refuseconnections
returns
.sm TRUE
if incoming SMTP connections should be refused.
The current implementation is based exclusively on the current load average
and the refuse load average option
(option
.b X ,
global variable
.i RefuseLA ):
.(b
bool
refuseconnections()
{
return (RefuseLA > 0 && CurrentLA >= RefuseLA);
}
.)b
A more clever implementation
could look at more system resources.
.sh 3 "Load Average Computation"
.pp
The routine
.i getla
returns the current load average (as a rounded integer).
The distribution includes several possible implementations.
If you are porting to a new environment
you may need to add some new tweaks.**
.(f
**If you do, please send updates to
sendmail@Sendmail.ORG.
.)f
.sh 2 "Configuration in sendmail/daemon.c"
.pp
The file
.i sendmail/daemon.c
contains a number of routines that are dependent
on the local networking environment.
The version supplied assumes you have BSD style sockets.
.pp
In previous releases,
we recommended that you modify the routine
.i maphostname
if you wanted to generalize
.b $[
&...&
.b $]
lookups.
We now recommend that you create a new keyed map instead.
.sh 1 "ACKNOWLEDGEMENTS"
.pp
I've worked on
.i sendmail
for many years,
and many employers have been remarkably patient
about letting me work on a large project
that was not part of my official job.
This includes time on the INGRES Project at
the University of California at Berkeley,
at Britton Lee,
and again on the Mammoth and Titan Projects at Berkeley.
.pp
Much of the second wave of improvements
resulting in version 8.1
should be credited to Bryan Costales of the
International Computer Science Institute.
As he passed me drafts of his book on
.i sendmail
I was inspired to start working on things again.
Bryan was also available to bounce ideas off of.
.pp
Gregory Neil Shapiro
of Worcester Polytechnic Institute
has become instrumental in all phases of
.i sendmail
support and development,
and was largely responsible for getting versions 8.8 and 8.9
out the door.
.pp
Many, many people contributed chunks of code and ideas to
.i sendmail .
It has proven to be a group network effort.
Version 8 in particular was a group project.
The following people and organizations made notable contributions:
.(l
John Beck, Hewlett-Packard & Sun Microsystems
Keith Bostic, CSRG, University of California, Berkeley
Andrew Cheng, Sun Microsystems
Michael J. Corrigan, University of California, San Diego
Bryan Costales, International Computer Science Institute & InfoBeat
Pa*:r (Pell) Emanuelsson
Craig Everhart, Transarc Corporation
Per Hedeland, Ericsson
Tom Ivar Helbekkmo, Norwegian School of Economics
Kari Hurtta, Finnish Meteorological Institute
Allan E. Johannesen, WPI
Jonathan Kamens, OpenVision Technologies, Inc.
Takahiro Kanbe, Fuji Xerox Information Systems Co., Ltd.
Brian Kantor, University of California, San Diego
John Kennedy, Cal State University, Chico
Murray S. Kucherawy, HookUp Communication Corp.
Bruce Lilly, Sony U.S.
Karl London
Motonori Nakamura, Ritsumeikan University & Kyoto University
John Gardiner Myers, Carnegie Mellon University
Neil Rickert, Northern Illinois University
Gregory Neil Shapiro, WPI
Eric Schnoebelen, Convex Computer Corp.
Eric Wassenaar, National Institute for Nuclear and High Energy Physics, Amsterdam
Randall Winchester, University of Maryland
Christophe Wolfhugel, Pasteur Institute & Herve Schauer Consultants (Paris)
Exactis.com, Inc.
.)l
I apologize for anyone I have omitted, misspelled, misattributed, or
otherwise missed.
At this point, I suspect that at least a hundred people
have contributed code,
and many more have contributed ideas, comments, and encouragement.
I've tried to list them in the RELEASE_NOTES in the distribution directory.
I appreciate their contribution as well.
.pp
Special thanks are reserved for Michael Corrigan and Christophe Wolfhugel,
who besides being wonderful guinea pigs and contributors
have also consented to be added to the ``sendmail@Sendmail.ORG'' list
and, by answering the bulk of the questions sent to that list,
have freed me up to do other work.
.++ A
.+c "COMMAND LINE FLAGS"
.ba 0
.nr ii 1i
.pp
Arguments must be presented with flags before addresses.
The flags are:
.ip -bfIxfP
Set operation mode to
.i x .
Operation modes are:
.(b
.ta 4n
m Deliver mail (default)
s Speak SMTP on input side
a(dg ``Arpanet'' mode (get envelope sender information from header)
d Run as a daemon in background
D Run as a daemon in foreground
t Run in test mode
v Just verify addresses, don't collect or deliver
i Initialize the alias database
p Print the mail queue
.)b
.(f
(dgDeprecated.
.)f
.ip -BfItypefP
Indicate body type.
.ip -CfIfilefP
Use a different configuration file.
.i Sendmail
runs as the invoking user (rather than root)
when this flag is specified.
.ip -dfIlevelfP
Set debugging level.
.ip "-f fIaddrfP"
The sender's machine address is
.i addr .
.ip -F fInamefP
Sets the full name of this user to
.i name .
.ip -G
When accepting messages via the command line,
indicate that they are for relay (gateway) submission.
sendmail may complain about syntactically invalid messages,
e.g., unqualified host names,
rather than fixing them when this flag is set.
sendmail will not do any canonicalization in this mode.
.ip "-h fIcntfP"
Sets the
.q "hop count"
to
.i cnt .
This represents the number of times this message has been processed
by
.i sendmail
(to the extent that it is supported by the underlying networks).
.i Cnt
is incremented during processing,
and if it reaches
MAXHOP
(currently 30)
.i sendmail
throws away the message with an error.
.ip "-L fItagfP"
Sets the identifier used for syslog.
Note that this identifier is set
as early as possible.
However,
.i sendmail
may be used
if problems arise
before the command line arguments
are processed.
.ip -n
Don't do aliasing or forwarding.
.ip "-N fInotificationsfP"
Tag all addresses being sent as wanting the indicated
.i notifications ,
which consists of the word
.q NEVER
or a comma-separated list of
.q SUCCESS ,
.q FAILURE ,
and
.q DELAY
for successful delivery,
failure,
and a message that is stuck in a queue somewhere.
The default is
.q FAILURE,DELAY .
.ip "-r fIaddrfP"
An obsolete form of
.b -f .
.ip -ofIx|valuefP
Set option
.i x
to the specified
.i value .
These options are described in Section 5.6.
.ip -OfIoptionfPfB=fPfIvaluefP
Set
.i option
to the specified
.i value
(for long form option names).
These options are described in Section 5.6.
.ip -MfIx|value
Set macro
.i x
to the specified
.i value .
.ip -pfIprotocolfP
Set the sending protocol.
Programs are encouraged to set this.
The protocol field can be in the form
.i protocol c
.b : c
.i host
to set both the sending protocol and sending host.
For example,
.q -pUUCP:uunet
sets the sending protocol to UUCP
and the sending host to uunet.
(Some existing programs use -oM to set the r and s macros;
this is equivalent to using -p.)
.ip -qfItimefP
Try to process the queued up mail.
If the time is given,
a
.i sendmail
will run through the queue at the specified interval
to deliver queued mail;
otherwise, it only runs once.
.ip -qfIXstringfP
Run the queue once,
limiting the jobs to those matching
.i Xstring .
The key letter
.i X
can be
.b I
to limit based on queue identifier,
.b R
to limit based on recipient,
or
.b S
to limit based on sender.
A particular queued job is accepted if one of the corresponding addresses
contains the indicated
.i string .
Multiple
.i -qfIXfP
flags are permitted,
with items with the same key letter
.q or'ed
together, and items with different key letters
.q and'ed
together.
.ip "-R ret"
What information you want returned if the message bounces;
.i ret
can be
.q HDRS
for headers only or
.q FULL
for headers plus body.
This is a request only;
the other end is not required to honor the parameter.
If
.q HDRS
is specified local bounces also return only the headers.
.ip -t
Read the header for
.q To: ,
.q Cc: ,
and
.q Bcc:
lines, and send to everyone listed in those lists.
The
.q Bcc:
line will be deleted before sending.
Any addresses in the argument vector will be deleted
from the send list.
.ip "-U"
Indicate that this is an initial User Agent submission.
This flag is deprecated.
Future releases will ignore this flag and
assume all submissions from the command line are
initial submissions.
.ip "-V envid"
The indicated
.i envid
is passed with the envelope of the message
and returned if the message bounces.
.ip "-X fIlogfilefP"
Log all traffic in and out of
.i sendmail
in the indicated
.i logfile
for debugging mailer problems.
This produces a lot of data very quickly and should be used sparingly.
.pp
There are a number of options that may be specified as
primitive flags.
These are the e, i, m, and v options.
Also,
the f option
may be specified as the
.b -s
flag.
The DSN related options
.q "-N" ,
.q "-R" ,
and
.q "-V"
have no effects on
.i sendmail
running as daemon.
.+c "QUEUE FILE FORMATS"
.pp
This appendix describes the format of the queue files.
These files live in the directory defined by the
.b Q
option in the
.i sendmail.cf
file, usually
.i /var/spool/mqueue
or
.i /usr/spool/mqueue .
The individual qf, df, and xf files
may be stored in separate
.i qf/ ,
.i df/ ,
and
.i xf/
subdirectories
if they are present in the queue directory.
.pp
To use multiple queues,
supply a value ending with an asterisk.
For example,
.i /var/spool/mqueue/q*
will use all of the directories or symbolic links to directories
beginning with `q' in
.i /var/spool/mqueue
as queue directories.
New messages will be randomly placed
into one of the queues.
Do not change the queue directory structure
while sendmail is running.
.pp
All queue files have the name
fIxfP|fBffPfIYMDhmsNPPPPPfP
where
.i YMDhmsNPPPPP
is the
.i id
for this message
and the
.i x
is a type.
The individual letters in the
.i id
are:
.nr ii 0.5i
.ip Y
Encoded year
.ip M
Encoded month
.ip D
Encoded day
.ip h
Encoded hour
.ip m
Encoded minute
.ip s
Encoded second
.ip N
Envelope number
.ip PPPPP
First five digits of the process ID
.pp
All files with the same id collectively define one message.
If memory-buffered files are available,
some of these files may never appear
on disk.
.pp
The types are:
.nr ii 0.5i
.ip d
The data file.
The message body (excluding the header) is kept in this file.
.ip q
The queue control file.
This file contains the information necessary to process the job.
.ip t
A temporary file.
These are an image of the
.b qf
file when it is being rebuilt.
It should be renamed to a
.b qf
file very quickly.
.ip x
A transcript file,
existing during the life of a session
showing everything that happens
during that session.
.pp
The
.b qf
file is structured as a series of lines
each beginning with a code letter.
The lines are as follows:
.ip V
The version number of the queue file format,
used to allow new
.i sendmail
binaries to read queue files created by older versions.
Defaults to version zero.
Must be the first line of the file if present.
For 8.10 the version number is 3.
.ip H
A header definition.
There may be any number of these lines.
The order is important:
they represent the order in the final message.
These use the same syntax
as header definitions in the configuration file.
.ip C
The controlling address.
The syntax is
.q localuser:aliasname .
Recipient addresses following this line
will be flagged so that deliveries will be run as the
.i localuser
(a user name from the /etc/passwd file);
.i aliasname
is the name of the alias that expanded to this address
(used for printing messages).
.ip Q
The ``original recipient'',
specified by the ORCPT= field in an ESMTP transaction.
Used exclusively for Delivery Status Notifications.
It applies only to the immediately following `R' line.
.ip R
A recipient address.
This will normally be completely aliased,
but is actually realiased when the job is processed.
There will be one line
for each recipient.
Version 1 qf files
also include a leading colon-terminated list of flags,
which can be
`S' to return a message on successful final delivery,
`F' to return a message on failure,
`D' to return a message if the message is delayed,
`B' to indicate that the body should be returned,
`N' to suppress returning the body,
and
`P' to declare this as a ``primary'' (command line or SMTP-session) address.
.ip S
The sender address.
There may only be one of these lines.
.ip T
The job creation time.
This is used to compute when to time out the job.
.ip P
The current message priority.
This is used to order the queue.
Higher numbers mean lower priorities.
The priority changes
as the message sits in the queue.
The initial priority depends on the message class
and the size of the message.
.ip M
A message.
This line is printed by the
.i mailq
command,
and is generally used to store status information.
It can contain any text.
.ip F
Flag bits, represented as one letter per flag.
Defined flag bits are
.b r
indicating that this is a response message
and
.b w
indicating that a warning message has been sent
announcing that the mail has been delayed.
.ip N
The total number of delivery attempts.
.ip K
The time (as seconds since January 1, 1970)
of the last delivery attempt.
.ip I
The i-number of the data file;
this can be used to recover your mail queue
after a disastrous disk crash.
.ip $
A macro definition.
The values of certain macros
(as of this writing, only
.b $r
and
.b $s )
are passed through to the queue run phase.
.ip B
The body type.
The remainder of the line is a text string defining the body type.
If this field is missing,
the body type is assumed to be
.q "undefined"
and no special processing is attempted.
Legal values are
.q 7BIT
and
.q 8BITMIME .
.ip Z
The original envelope id (from the ESMTP transaction).
For Deliver Status Notifications only.
.pp
As an example,
the following is a queue file sent to
.q eric@mammoth.Berkeley.EDU
and
.q bostic@okeeffe.CS.Berkeley.EDU **:
.(f
**This example is contrived and probably inaccurate for your environment.
Glance over it to get an idea;
nothing can replace looking at what your own system generates.
.)f
.(b
P835771
T404261372
Seric
Ceric:sendmail@vangogh.CS.Berkeley.EDU
Reric@mammoth.Berkeley.EDU
Rbostic@okeeffe.CS.Berkeley.EDU
H?P?Return-path: <owner-sendmail@vangogh.CS.Berkeley.EDU>
HReceived: by vangogh.CS.Berkeley.EDU (5.108/2.7) id AAA06703;
Fri, 17 Jul 1992 00:28:55 -0700
HReceived: from mail.CS.Berkeley.EDU by vangogh.CS.Berkeley.EDU (5.108/2.7)
id AAA06698; Fri, 17 Jul 1992 00:28:54 -0700
HReceived: from [128.32.31.21] by mail.CS.Berkeley.EDU (5.96/2.5)
id AA22777; Fri, 17 Jul 1992 03:29:14 -0400
HReceived: by foo.bar.baz.de (5.57/Ultrix3.0-C)
id AA22757; Fri, 17 Jul 1992 09:31:25 GMT
H?F?From: eric@foo.bar.baz.de (Eric Allman)
H?x?Full-name: Eric Allman
HMessage-id: <9207170931.AA22757@foo.bar.baz.de>
HTo: sendmail@vangogh.CS.Berkeley.EDU
HSubject: this is an example message
.)b
This shows
the person who sent the message,
the submission time
(in seconds since January 1, 1970),
the message priority,
the message class,
the recipients,
and the headers for the message.
.+c "SUMMARY OF SUPPORT FILES"
.pp
This is a summary of the support files
that
.i sendmail
creates or generates.
Many of these can be changed by editing the sendmail.cf file;
check there to find the actual pathnames.
.nr ii 1i
.ip "/usr/*(SD/sendmail"
The binary of
.i sendmail .
.ip /usr/*(SB/newaliases
A link to /usr/*(SD/sendmail;
causes the alias database to be rebuilt.
Running this program is completely equivalent to giving
.i sendmail
the
.b -bi
flag.
.ip /usr/*(SB/mailq
Prints a listing of the mail queue.
This program is equivalent to using the
.b -bp
flag to
.i sendmail .
.ip /etc/mail/sendmail.cf
The configuration file,
in textual form.
.ip /etc/mail/helpfile
The SMTP help file.
.ip /etc/mail/statistics
A statistics file; need not be present.
.ip /etc/mail/sendmail.pid
Created in daemon mode;
it contains the process id of the current SMTP daemon.
If you use this in scripts;
use ``head -1'' to get just the first line;
the second line contains the command line used to invoke the daemon,
and later versions of
.i sendmail
may add more information to subsequent lines.
.ip /etc/mail/aliases
The textual version of the alias file.
.ip /etc/mail/aliases.db
The alias file in
.i hash |(3)
format.
.ip /etc/mail/aliases.{pag,dir}
The alias file in
.i ndbm |(3)
format.
.ip /var/spool/mqueue
The directory in which the mail queue(s)
and temporary files reside.
.ip /var/spool/mqueue/qf*
Control (queue) files for messages.
.ip /var/spool/mqueue/df*
Data files.
.ip /var/spool/mqueue/tf*
Temporary versions of the qf files,
used during queue file rebuild.
.ip /var/spool/mqueue/xf*
A transcript of the current session.
.if o
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.".ro
.".ls 1
.".tp
.".sp 2i
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.".sz 24
.".b SENDMAIL
.".sz 14
.".sp
."INSTALLATION AND OPERATION GUIDE
.".sp
.".sz 10
."Eric Allman
.".sp
."Version $Revision: 8.293 $
.".ce 0
.bp 3
.ce
.sz 12
TABLE OF CONTENTS
.sz 10
.sp
." remove some things to avoid "out of temp file space" problem
.rm sh
.rm (x
.rm )x
.rm ip
.rm pp
.rm lp
.rm he
.rm fo
.rm eh
.rm oh
.rm ef
.rm of
.xp
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