Chapter 5. Command Switches, Debugging, and References

Table of Contents
5.1 Switches
5.2 Debugging
5.3 References

In this section we will discuss the use of command switches, some debugging tools and some references available for sendmail.

5.1 Switches

The sendmail man page lists all of the switches. Here's the text from the man page for sendmail (with some comments inserted):


SENDMAIL(8)		 UNIX System Manager's Manual		   SENDMAIL(8)

NAME
     sendmail - an electronic mail transport agent

SYNOPSIS
     sendmail [flags] [address ...]
     newaliases
     mailq [-v]

DESCRIPTION
     Sendmail sends a message to one or more recipients, routing the message
     over whatever networks are necessary.  Sendmail does internetwork for-
     warding as necessary to deliver the message to the correct place.

     Sendmail is not intended as a user interface routine; other programs pro-
     vide user-friendly front ends; sendmail is used only to deliver pre-for-
     matted messages.

     With no flags, sendmail reads its standard input up to an end-of-file or
     a line consisting only of a single dot and sends a copy of the message
     found there to all of the addresses listed.  It determines the network(s)
     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, e.g., if
     `john' sends to `group', and `group' includes `john' in the expansion,
     then the letter will not be delivered to `john'.

   Parameters

     -Btype	 Set the body type to type. Current legal values 7BIT or
		 8BITMIME.

     -ba	 Go into ARPANET mode.	All input lines must end with a CR-LF,
		 and all messages will be 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.  This requires Berkeley IPC. Sendmail will
		 fork and run in background listening on socket 25 for incom-
		 ing SMTP connections.	This is normally run from /etc/rc.

     -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.

     -bm	 Deliver mail in the usual way (default).

     -bp	 Print a listing of the queue.

     -bs	 Use the SMTP protocol as described in RFC821 on standard in-
		 put and output.  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 configu-


		 ration tables.

     -bv	 Verify names only - do not try to collect or deliver a mes-
		 sage.	Verify mode is normally used for validating users or
		 mailing lists.

     -Cfile	 Use alternate configuration file.  Sendmail refuses to run as
		 root if an alternate configuration file is specified.

     -dX	 Set debugging value to X.

     -Ffullname	 Set the full name of the sender.

     -fname	 Sets the name of the ``from'' person (i.e., the sender of the
		 mail).	 -f can only be used by ``trusted'' users (normally
		 root, daemon, and network) or if the person you are trying to
		 become is the same as the person you are.

     -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 mes-
		 sages.	 This should be set if you are reading data from a
		 file.

     -N dsn	 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.

     -O option=value
		 Set option option to the specified value. This form uses long
		 names.	 See below for more details.

     -ox value	 Set option x to the specified value. This form uses single
		 character names only.	The short names are not described in
		 this manual page; see the Sendmail Installation and Operation
		 Guide for details.

     -pprotocol	 Set the name of the protocol used to receive the message.
		 This can be a simple protocol name such as ``UUCP'' or a pro-
		 tocol and hostname, such as ``UUCP:ucbvax''.

     -q[time]	 Processed 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 exam-
		 ple, `-q1h30m' or `-q90m' would 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.

     -qIsubstr	 Limit processed jobs to those containing substr as a sub-
		 string of the queue id.

     -qRsubstr	 Limit processed jobs to those containing substr as a sub-
		 string of one of the recipients.

     -qSsubstr	 Limit processed jobs to those containing substr as a sub-
		 string of the sender.

     -R return	 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.

     -t		 Read message for recipients.  To:, Cc:, and Bcc: lines will
		 be scanned for recipient addresses.  The Bcc: line will be
		 deleted before transmission.

     -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.

     -V envid	 Set the original envelope id.	This is propagated across SMTP
		 to servers that support DSNs and is returned in DSN-compliant
		 error messages.

     -v		 Go into verbose mode.	Alias expansions will be announced,
		 etc.

     -X logfile	 Log all traffic in and out of mailers in the indicated log
		 file.	This should only be used as a last resort for debug-
		 ging mailer bugs.  It will log a lot of data very quickly.

     --		 Stop processing command flags and use the rest of the argu-
		 ments as addresses.

   Options
     There are also a number of processing options that may be set.  Normally
     these will only be used by a system administrator.	 Options may 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.  This is a partial
     list limited to those options that are likely to be useful on the command
     line and only shows the long names; for a complete list (and details),
     consult the Sendmail Installation and Operation Guide. The options are:

     AliasFile=file
		 Use alternate alias file.

     HoldExpensive
		 On mailers that are considered ``expensive'' to connect to,
		 don't initiate immediate connection.  This requires queueing.

     CheckpointInterval=N
		 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
		 Set the delivery mode to x. Delivery modes are `i' for inter-
		 active (synchronous) delivery, `b' for background (asyn-
		 chronous) delivery, `q' for queue only - i.e., actual deliv-
		 ery is done the next time the queue is run, and `d' for de-
		 ferred - the same as `q' except that database lookups (no-
		 tably DNS and NIS lookups) are avoided.

     ErrorMode=x
		 Set error processing to mode x. Valid modes are `m' to mail
		 back the error message, `w' to ``write'' back the error mes-
		 sage (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), and `e' to do
		 special processing for the BerkNet.  If the text of the mes-
		 sage 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.

     SaveFromLine
		 Save UNIX-style From lines at the front of messages.

     MaxHopCount= N
		 The maximum number of times a message is allowed to ``hop''
		 before we decide it is in a loop.

     IgnoreDots	 Do not take dots on a line by themselves as a message termi-
		 nator.

     SendMimeErrors
		 Send error messages in MIME format.  If not set, the DSN (De-
		 livery Status Notification) SMTP extension is disabled.

     ConnectionCacheTimeout=timeout
		 Set connection cache timeout.

     ConnectionCacheSize=N
		 Set connection cache size.

     LogLevel=n	 The log level.

     MeToo	 Send to ``me'' (the sender) also if I am in an alias expan-
		 sion.

     CheckAliases
		 Validate the right hand side of aliases during a newalias-
		 es(1) command.

     OldStyleHeaders
		 If set, this message may have old style headers.  If not set,
		 this message is guaranteed to have new style headers (i.e.,
		 commas instead of spaces between addresses).  If set, an
		 adaptive algorithm is used that will correctly determine the
		 header format in most cases.

     QueueDirectory=queuedir
		 Select the directory in which to queue messages.

     StatusFile=file
		 Save statistics in the named file.

     Timeout.queuereturn=time
		 Set the timeout on undelivered messages in the queue to the
		 specified time.  After delivery has failed (e.g., because of
		 a host being down) for this amount of time, failed messages
		 will be returned to the sender.  The default is five days.

     UserDatabaseSpec=userdatabase
		 If set, a user database is consulted to get forwarding infor-
		 mation.  You can consider this an adjunct to the aliasing
		 mechanism, except that the database is intended to be dis-
		 tributed; aliases are local to a particular host.  This may
		 not be available if your sendmail does not have the USERDB
		 option compiled in.

     ForkEachJob
		 Fork each job during queue runs.  May be convenient on memo-
		 ry-poor machines.

     SevenBitInput

		 Strip incoming messages to seven bits.

     EightBitMode=mode
		 Set the handling of eight bit input to seven bit destinations
		 to mode: m (mimefy) will convert to seven-bit MIME format, p
		 (pass) will pass it as eight bits (but violates protocols),
		 and s (strict) will bounce the message.

     MinQueueAge=timeout
		 Sets how long a job must ferment in the queue between at-
		 tempts to send it.

     DefaultCharSet=charset
		 Sets the default character set used to label 8-bit data that
		 is not otherwise labelled.

     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: none leaves the mes-
		 sage 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, and 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.

     In aliases, the first character of a name may be a vertical bar to cause
     interpretation of the rest of the name as a command to pipe the mail to.
     It may be necessary to quote the name to keep sendmail from suppressing
     the blanks from between arguments.	 For example, a common alias is:

	   msgs: "|/usr/bin/msgs -s"

     Aliases may also have the syntax ``:include:filename'' to ask sendmail to
     read the named file for a list of recipients.  For example, an alias such
     as:

	   poets: ":include:/usr/local/lib/poets.list"

     would read /usr/local/lib/poets.list for the list of addresses making up
     the group.

     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	   Host name not recognized.
	   EX_TEMPFAIL	   Message could not be sent immediately, but was
			   queued.

     If invoked as newaliases, sendmail will rebuild the alias database.  If
     invoked as mailq, sendmail will print the contents of the mail queue.

FILES
     Except for the file /etc/sendmail.cf itself and the daemon process ID
     file, the following pathnames are all specified in /etc/sendmail.cf.
     Thus, these values are only approximations.

     /etc/aliases	   raw data for alias names
     /etc/aliases.db	   data base of alias names
     /etc/sendmail.cf	   configuration file
     /etc/sendmail.hf	   help file
     /var/log/sendmail.st  collected statistics
     /var/spool/mqueue/*   temp files

SEE ALSO
     binmail(1),  mail(1),  rmail(1),  syslog(3),  aliases(5),	mailaddr(7),
     rc(8);

     DARPA Internet Request For Comments RFC819, RFC821, RFC822.

     Sendmail - An Internetwork Mail Router, No. 9, SMM.

     Sendmail Installation and Operation Guide, No. 8, SMM.

HISTORY
     The sendmail command appeared in 4.2BSD.

4th Berkeley Distribution	August 2, 1998				     6