sendmail(1M) sendmail(1M)
NAME
sendmail, mailq - send network mail
SYNOPSIS
/usr/lib/sendmail [ flags ] [ address ... ]
mailq
newaliases
DESCRIPTION
sendmail sends a message to one or more recipients, routing the message
over whatever networks are necessary. sendmail does internetwork
forwarding as necessary to deliver the message to the correct place.
sendmail is not intended as a user-interface routine; other programs
provide user-friendly front ends; sendmail is used only to deliver
preformatted messages.
With no flags, sendmail reads its standard input up to an end-of-file or
a line with a single dot and sends a copy of the letter found there to
all of the addresses listed. It determines the networks to use based on
the syntax and contents of the addresses.
Local addresses are looked up in a file and aliased appropriately.
Aliasing can be prevented by preceding the address with a backslash.
Normally the sender is not included in any alias expansions, for example,
if john sends to group, and group includes john in the expansion, the
letter is not delivered to john.
flags (command line options) are:
-Btype Set the body type to type. Current legal types are 7BIT or
8BITMIME.
-ba Go into ARPANET mode. All input lines must end with a CR-LF,
and all messages are generated with a CR-LF at the end. Also,
the From: and Sender: fields are examined for the name of the
sender.
-bd Run as a daemon.
-bD Same as -bd except runs in foreground.
-bh Print the persistent host status database.
-bH Purge the persistent host status database.
-bi Initialize the alias database.
Page 1
sendmail(1M) sendmail(1M)
-bm Deliver mail in the usual way (default).
-bp Print a listing of the queue.
-bs Use the SMTP protocol as described in RFC-821. This flag
implies all the operations of the -ba flag that are compatible
with SMTP.
-bt Run in address test mode. This mode reads addresses and shows
the steps in parsing; it is used for debugging configuration
tables.
-bv Verify names only -- do not try to collect or deliver a
message. Verify mode is normally used for validating users or
mailing lists. Note that this will only check the ability for
the current system to deliver to an address, and does not
verify the existance of that address on remote systems.
-bz Create the configuration freeze file. For security reasons,
only superuser can use this mode.
-Cfile Use alternate configuration file. If file is not specified,
sendmail.cf in the current directory is used. For security
reasons, sendmail refuses to run as root if an alternate
configuration file is specified.
-dX[.Y] Set debugging value X to level Y (defaults to level 1)
-ex Identical to the e option (see below).
-Ffullname Set the full name of the sender.
-fname Sets the name of the "from" person (the sender of the mail).
-hN Set the hop count to N. The hop count is incremented every
time the mail is processed. When it reaches a limit, the mail
is returned with an error message, the victim of an aliasing
loop. If not specified, Received: lines in the message are
counted.
-i Ignore dots alone on lines by themselves in incoming messages.
This should be set if you are reading data from a file.
-N Set delivery status notification conditions to dsn, which can
be `never' for no notifications or a comma separated list of
the values `failure' to be notified if delivery failed,
`delay' to be notified if delivery is delayed, and `success'
to be notified when the message is successfully delivered.
-n Don't do aliasing.
Page 2
sendmail(1M) sendmail(1M)
-Ooption=value
Set option option to the specified value. This form uses long
names. Some options are described below.
-oXvalue Set option X to the specified value. This form uses single
character names only. Some options are described below.
-pprotocol Set the name of the protocol used to receive the message.
This can be a simple protocol name such as UUCP or a protocol
and hostname, such as UUCP:ucbvax.
-qtime Process saved messages in the queue at given intervals. If
time is omitted, process the queue once. Time is given as a
tagged number, with `s' being seconds, `m' being minutes, `h'
being hours, `d' being days, and `w' being weeks. For
example, `-q1h30m' or `-q90m' both set the timeout to one hour
thirty minutes. If time is specified, sendmail will run in
background. This option can be used safely with -bd .
-qIsubtr Limit processed jobs to those containing substr as a substring
of the queue id
-qRsubtr Limit processed jobs to those containing substr as a substring
of the recipients
-qSsubtr Limit processed jobs to those containing substr as a substring
of the sender
-Rreturn Set the amount of the message to be returned if the message
bounces. The return parameter can be `full' to return the
entire message or `hdrs' to return only the headers.
-rname An alternate and obsolete form of the -f flag.
-s Same as setting the f option (see below).
-t Read message for recipients. To:, Cc:, and Bcc: lines are
scanned for people to send to. The Bcc: line is deleted
before transmission. Any addresses in the argument list are
suppressed, that is, they do not receive copies even if listed
in the message header.
-U Initial (user) submission. This should always be set when
called from a user agent such as Mail or exmh and never be set
when called by a network delivery agent such as rmail.
-Venvid Set the original envelope id. This is propagated across SMTP
to servers that support DSNs and is returned in DSN-compliant
error messages.
Page 3
sendmail(1M) sendmail(1M)
-v Go into verbose mode. Alias expansions are announced and so
on.
-Xlogfile Log all traffic in and out of mailers in the indicated log
file. This should only be used as a last resort for debugging
mailer bugs. It logs a lot of data very quickly.
-Zfile Define alternate freeze file. For security reasons, only
superuser can use this flag.
There are a number of processing options that can be set. Normally these
are only used by a system administrator. Options can be set either on
the command line using the -o flag (for short names), the -O flag (for
long names), or in the configuration file. Both the long names and short
(single character) names are listed here. These are described in detail
in the IRIX Admin: Networking and Mail guide.
Options are:
AliasFile=file
Afile Use alternate alias file.
AliasWait=N
aN If the alias database is being rebuilt by another process,
wait up to N minutes for the rebuild to finish. If the alias
database is not rebuilt in N minutes, rebuild the database (if
the D option is set) or issue a warning.
BlankSub=c
Bc Set the blank substitution character to c. Unquoted spaces in
addresses are replaced by this character.
MinFreeBlocks=nblocks
bnblocks[/maxmsgsize]
Set the minimum number of free blocks needed on the spool
filesystem to accept any message and the maximum allowable
message size. If the spool filesystem is too full or the
message size is too large, mail is rejected. Default values
are 0 and infinite respectively.
HoldExpensive
c On mailers that are considered expensive to connect to, don't
initiate immediate connection. This requires queueing.
CheckpointInterval=N
CN Checkpoint the queue file after every N successful deliveries
(default 10). This avoids excessive duplicate deliveries when
sending to long mailing lists interrupted by system crashes.
DeliveryMode=x
Page 4
sendmail(1M) sendmail(1M)
dx Set the delivery mode to x. Only the first character of the
mode is significant. Delivery modes are background for
background (asynchronous) delivery, defered for defered (hold
as is) delivery. interactive for interactive (synchronous)
delivery, and q for queue only -- actual delivery is done the
next time the queue is run.
AutoRebuildAliases
D Try to automatically rebuild the alias database if necessary.
ErrorHeader=/file|format
E/file|format
Specify one or more headers to be added to error messages. If
the value passed to the E option begins with the / character,
the error header formats are read from the specified file.
The error header formats are macro-expanded before being
inserted into the error message.
ErrorMode=x
ex Set error processing to mode x. Valid modes are m to mail
back the error message, e like m, but always exist with a zero
exit status, w to write back the error message (or mail it
back if the sender is not logged in), p to print the errors on
the terminal (default), q to throw away error messages (only
exit status is returned.) If the text of the message is not
mailed back by modes m or w and if the sender is local to this
machine, a copy of the message is appended to the file
dead.letter in the sender's home directory.
TempFileMode=mode
Fmode The mode to use when creating temporary files. Modes are in
octal.
SaveFromLine
f Save UNIX-style From: lines at the front of messages.
MatchGecos
G Match local mail names against the GECOS portion of the
password file.
DefaultUser
gN The default group ID to use when calling mailers. This option
is deprecated in favor of the u mode.
HelpFile=file
Hfile The SMTP help file.
MaxHopCount=N
hN The maximum number of times a message is allowed to hop before
sendmail decides it is in a loop.
Page 5
sendmail(1M) sendmail(1M)
IgnoreDots
i Do not take dots on a line by themselves as a message
terminator. This is always disabled (that is, dots are always
accepted) when reading SMTP mail.
ForwardPath=path
Jpath Set the path for searching for users' .forward files. The
default is $z/.forward. path can also be set to a sequence of
paths separated by colons; sendmail stops at the first file it
can successfully and safely open.
SendMimeErrors
j If set, send error messages in MIME format (see RFC1341 and
RFC1344 for details).
ConnectionCacheTimeout=timeout
Ktimeout The maximum amount of time a cached connection is permitted to
idle without activity. The format of timeout is the same as
for the -q flag above. The default is five minutes.
ConnectionCacheSize=N
kN The maximum number of open connections that are cached at a
time. The default is one. Setting it to zero defaults to the
old behavior, that is, connections are closed immediately.
LogLevel=n
Ln Sets the log level. Causes sendmail to log informational
messages to the system SYSLOG. Higher values of n log
increasingly trivial information. Note that each level logs
its own information plus all information logged by lower
valued log levels. Possible values for n are:
0 No logging
1 Serious system failures and potential security problems
2 Network problems and protocol failures
3 Forwarding and received message errors
4 Minor errors
5 Received messages/message collection stats
6 Creation of error messages, VRFY and EXPN commands
7 Message delivery failures
8 Successful deliveries
9 Messages being deferred (due to a host being down and so
on)
10 Alias/forward expansion
12 Connecting hosts
20 Attempts to run locked queue files
21 Monitor load average computation and process counting.
UseErrorsTo
l If there is an Errors-To: header, send error messages to the
addresses listed there.
Page 6
sendmail(1M) sendmail(1M)
MXvalue Set macro X to the specified value. This option is intended
only for use from the command line.
MeToo
m Send to me (the sender) too, even if I am in an alias
expansion.
CheckAliases
n Validate the RHS when building the alias database.
OldStyleHeaders
o If set, this message can have old-style headers. If not set,
this message is guaranteed to have new-style headers (commas
instead of spaces between addresses). If set, an adaptive
algorithm is used that correctly determines the header format
in most cases.
PostMasterCopy=addr
Paddr Add addr to the Cc: list of all error messages.
PrivacyOptions=opt,opt,...
popt,opt,...
Set the privacy options. Privacy is really a misnomer; many
of these are just a way of insisting on stricter adherence to
the SMTP protocol. Possible opt values are:
authwarnings Add X-Authentication-Warning: headers
goaway Disallow essentially all SMTP status queries
needexpnhelo Insist on HELO or EHLO command before EXPN
needmailhelo Insist on HELO or EHLO command before MAIL
needvrfyhelo Insist on HELO or EHLO command before VRFY
noexpn Disallow EXPN entirely
novrfy Disallow VRFY entirely
noreceipts Ignore Return-Receipt-To: header
public Allow open access (the default)
restrictmailq Restrict mailq command restrictqrun Restrict
-q command line flag
R Normally, sendmail tries to eliminate any unnecessary explicit
routes when sending an error message. If the R option is set,
this is disabled, and the mail is sent to the first address in
the route.
Timeout.suboption=time
rtime Sets a number of different timeouts. If the old syntax is
used the mail, rcpt, datainit, datablock, datafinal,and
command values will be set. time is specified in the standard
sendmail manner. Valid suboptions are:
command Wait for the next command
connect Wait for the connect(2) to return
Page 7
sendmail(1M) sendmail(1M)
datablock Wait for each DATA block read
datafinal Wait for acknowledgment of final dot
datainit Wait for DATA acknowledgment
fileopen Wait for an NFS file to open
helo wait for HELO or EHLO
hoststatus Duration of host status
iconnect Wait for the first connect(2)
initial Wait for initial greeting message
mail Wait for MAIL acknowledgment
misc wait for other SMTP commands
queuereturn Bounce if still undelivered
queuewarn Warn if still undelivered
quit Wait for QUIT acknowledgment
rcpt Wait for RCPT acknowledgment
rset Wait for RSET acknowledgment
StatusFilefile
Sfile Save statistics in the named file.
SuperSafe
s Always instantiate the queue file, even under circumstances
where it is not strictly necessary.
QueueTimeout=time
Ttime Set the return and warning timeouts for messages in the queue
to the specified times. The format of time is the same as for
the -q flag above. If time is a positive value, messages that
sit in the queue for longer than time are returned to the
sender. The default is five days.
TimeZoneSpec
ttzinfo Set the local time zone info to tzinfo For example, PST8PDT.
If this value set but has no value the enviormentvariable TZ
is used. The IRIX sendmail correctly sets this variable
without a value by default.
DefaultUser=U[:G]
uU[:G] Set the default user ID to U. Set the default group ID to G.
FallbackMXhost=host
Vhost If specified, the host acts like a very low priority MX on
every host.
Verbose
v Run in verbose mode.
TryNullMXList
w If we are best MX, try host directly. (Set by default.)
RefuseLA=load
Page 8
sendmail(1M) sendmail(1M)
Xload When the system load average exceeds load, refuse incoming
SMTP connections.
QueueLA=load
xload When the system load average exceeds load, just queue messages
(don't try to send them).
ForkEachJob
Y Fork jobs during queue runs.
Recipientfactor=fact
yfact Work recipient factor. The indicated factor is added to the
priority (thus lowering the priority of the job) for each
recipient; this value penalizes jobs with large numbers of
recipients.
RetryFactor=fact
Zfact Work time factor. The factor is added to the priority every
time a job is processed. Thus, each time a job is processed,
its priority is decreased by the indicated value.
ClassFactor=fact
zfact Work message class factor. The indicated factor (determined
by the Precedence: field in the user header and the P lines in
the configuration file) and subtracted from the priority.
Thus, messages with a higher Priority: are favored.
SevenBitInput
7 Strip input to seven bits for compatibility with old systems.
This shouldn't be necessary.
EightBitMode=mode
8mode Set the handling of eight bit input to seven bit destinations
to mode `m' (mimeify) will convert to seven-bit MIME format,
mode `p' (pass) will pass it as eight bits (but violates
protocols), and mode `s' (strict) will bounce the message.
MinQueueAge=timeout
Sets how long a job must ferment in the queue between attempts
to send it.
DefaultCharSet=charset
Sets the default character set used to label 8-bit data that
is not otherwise labeled.
DialDelay=sleeptime
If opening a connection fails, sleep for sleeptime seconds and
try again. Useful on dial-on-demand sites.
NoRecipientAction=action
Set the behaviour when there are no recipient headers (To:,
Cc: or Bcc:) in the message to action:
Page 9
sendmail(1M) sendmail(1M)
none leaves the message unchanged.
add-to adds a To: header with the envelope
recipients.
add-apparently-to adds an Apparently-To: header with the
envelope recipients.
add-bcc adds an empty Bcc: header.
add-to-undisclosed adds a header reading ``To: undisclosed-
recipients:;''.
MaxDaemonChildren=N
Sets the maximum number of children that an incoming SMTP
daemon will allow to spawn at any time to N.
ConnectionRateThrottle= N
Sets the maximum number of connections per second to the SMTP
port to N.
DIAGNOSTICS
sendmail returns an exit status describing what it did. The codes are
defined in <sysexits.h>.
EX_OK Successful completion on all addresses.
EX_NOUSER User name not recognized.
EX_UNAVAILABLE Catchall meaning necessary resources were not available.
EX_SYNTAX Syntax error in address.
EX_SOFTWARE Internal software error, including bad arguments.
EX_OSERR Temporary operating system error, such as "cannot fork".
EX_NOHOST Hostname not recognized.
EX_TEMPFAIL Message could not be sent immediately, but was queued.
If invoked as newaliases (see newaliases(1M)), sendmail rebuilds the
alias database. If invoked as mailq, sendmail prints the contents of the
mail queue.
sendmail will log varying amounts via the syslog(3) facility depending on
the setting of the LogLevel (L) option.
Further statics can be gathered via use the the StatusFile option and the
mailstats(1m) program.
FORWARDING MAIL USING SENDMAIL
As a personal alternative to aliasing, a user can put a file with the
name .forward in his home directory. If this file exists, sendmail
redirects mail for that user to the list of recipients in the .forward
file. The recipients listed in the .forward file can be separated by
commas or newlines. Programs and files are valid recipients. For
example, if user jane has a .forward file containing:
jd@company.com
/usr/tmp/mail.log
|/usr/local/bin/mymailer
Page 10
sendmail(1M) sendmail(1M)
sendmail redirects all incoming messages for jane to jd@company.com,
append a copy of the message to the file /usr/tmp/mail.log (if it has o+w
permissions) and pipe a copy of the message to standard input of
/usr/local/bin/mymailer.
The user can redirect mail to himself in addition to sending it on to
other destinations. This is particularly useful in the event that the
user wishes to continue to receive mail in his own mailbox while passing
copies of each incoming message on to some alternative destination. For
example, if the home directory for user john contains a .forward file
with contents:
\john, "|/usr/sbin/vacation john"
sendmail appends each incoming message to john's regular mailbox and send
a copy of each message to the /usr/sbin/vacation program.
AUTOCONFIGURATION
The default IRIX sendmail.cf configuration file supports the IRIX
autoconfiguration feature.
This autoconfiguring sendmail.cf file works in conjunction with the
configmail(1M) script. When sendmail parses the autoconfiguring
sendmail.cf file, it is directed to call configmail to obtain the values
for all critical macros and classes. These values are calculated at
runtime by configmail.
For most mail environments, the calculated default values returned by
configmail should be sufficient to provide a working sendmail
configuration. In many cases, sendmail should be able to configure
itself and begin working without any user intervention.
In some situations, it may still be necessary or desirable to manually
configure some of the critical configuration parameters. When using the
autoconfiguring option, it should not be necessary to make any actual
changes to the sendmail.cf file itself in order to do this. The
configmail script provides interactive user interface modes to assist in
modifying the default configuration, verifying the current configuration
parameter settings and getting help information on the various
configuration parameters themselves. For example, a quick check and
adjustment of the most important configuration parameters can be done by
giving the command:
/usr/etc/configmail setup
Silicon Graphics Extensions
A number of extensions have been added to this version of sendmail.
These features may disapear in the future as stock sendmail provides
mechanisms to provide similar functionality.
Page 11
sendmail(1M) sendmail(1M)
The freeze file and the -bz and -Z options provide the ability to cache
the result of file includes and program executions to allow for quick
startup of sendmail. The format of the freeze file is similar to the
sendmail.cf file. Generation of the freeze file is performed
automaticly at boot time if the file /etc/sendmail.fc exists and is not
empty. Zero length freeze files are ignored.
The directory lookups can be made to via nsd(1M) by using the nsd class.
This lookup class is called nsd, and the file argument should be the nsd
table the lookup is requested in. eg: nsd:mail.aliases
The pathalias database will be used to route UUCP mail if a pathalias
database exists. This can be performed by using $[ and $] in rules. See
the distributed sendmail.cf for examples.
If the file /etc/shells exists it should contain a list of shells (one
per line) of shells that a user must have to use a | in a .forward file.
If this file does not exist the shells /bin/sh, /usr/bin/sh, /bin/csh,
/usr/bin/csh, /sbin/sh, /sbin/csh, /bin/ksh, /sbin/ksh, /usr/bin/ksh,
/bin/tcsh, /usr/bin/tcsh will be used as a default list. To disable
this feature (which can lead to security problems) put the line
``/SENDMAIL/ANY/SHELL/'' in /etc/shells.
Macros and Options defined in the sendmail.cf file (but not on the
command line) can be set to the output of a program. Examples of this
are in the distributed sendmail.cf.
The number of ``sendmail'' processes running on a system will be added to
the load average when checking QueueLA and RefuseLA. This functionality
can be disabled by adding ",l" to the option value. (eg: Ox20,l)
If you system is setup to use capabilities, access control lists, and
trusted networking sendmail will support it.
A line containing ``+:+'' in the /etc/alias file will automaticly enable
NIS alias support. This will produce redundant NIS requests if nsd is
used for aliases lookups, and nsd is configured to use nis for aliases.
The existance of the file /etc/resolv.conf enables DNS and MX support in
sendmail. On systems that are not configured to support DNS, this file
MUST not exist.
FILES
/etc/sendmail.cf configuration file (with autoconfiguration
support)
/etc/sendmail.fc frozen configuration
~/.forward optional per-user forwarding targets
The following filenames are actually specified in /etc/sendmail.cf, thus,
these values are only approximations.
Page 12
sendmail(1M) sendmail(1M)
/bin/mail to deliver local mail
/bin/rmail to receive uucp mail
/usr/etc/configmail autoconfiguration script
/etc/aliases plain text file of system aliases
/etc/aliases.{pag,dir} data base of system aliases
/etc/sendmail.hf help file
/var/sendmail.st collected statistics
/usr/bin/uux to deliver uucp mail
/usr/spool/mqueue/* temp files
SEE ALSO
configmail(1M), mail_att(1), mail_bsd(1), mailstats(1m), makemap(1m),
rc2(1M), rmail(1M), vacation(1), resolver(3N), syslog(3C), aliases(4).
Internet Requests For Comments RFC-819, RFC-821, RFC-822.
IRIX Admin: Networking and Mail
sendmail (2nd Edition) by Bryan Costales with Eric Allman and Neil
Rickert, O'Reilly & Associates, Inc. ISBN 1-56592-222-0
WARNING
Alias loops are a notorious problem with electronic mail. With sendmail,
you must be especially careful when using both local (/etc/aliases and
.forward files) and domain-wide (NIS) aliases. For example, if user john
moves from machine iris1 to machine iris2 it may, at first glance, seem
logical to just add a local alias on iris1 that forwards mail for john to
john@iris2. However, if you have neglected to update the NIS aliases
database, an alias loop results. This happens because upon receiving
mail to john@iris2, host iris2 attempts to find john in the local and NIS
aliases databases. If the entry for john has not been properly updated,
it can still point to john@iris1.
Page 13