Mail Administration Guide

Appendix B `sendmail` Options

`sendmail` Command-Line Arguments

Use command-line arguments on the /usr/lib/sendmail command line. Table B-1 describes these arguments.

Table B-1 sendmail Command-Line Arguments


Argument	Description
`-Btype`	Select the body type (7BIT or 8BITMIME).
`-bx`	Set operation mode to `x`; operation modes are:
	`a`	Run in ARPANET mode.
	`d`	Run as a daemon.
	`i`	Initialize the alias database.
	`m`	Deliver mail (default).
	`p`	Print the mail queue.
	`s`	Use SMTP on input side.
	`t`	Run in test mode.
	`v`	Just verify recipients.
`-Cfile`	Use a different configuration file.
`-dlevel`	Set debugging level.
`-Fname`	Set the full name of this user to `name`.
`-fname`	An obsolete form of `-r`.
`-hcnt`	Set the "hop count" to `cnt`. It sets the number of times this message has been processed by `sendmail` (to the extent that it is supported by the underlying networks). `cnt` is incremented during processing, and if it reaches the value of configuration option `-h`, `sendmail` returns the message with an error.
`-Mid`	Attempt to deliver the queued with the message-id `id`.
`-n`	Do not do aliasing or forwarding.
`-oxvalue`	Set configuration option `x` to the specified `value`.
`-pprotocol`	Set the sending protocol; you can enter the `protocol` field as `protocol`:`host` to set both the protocol and the sending host.
`-qtime`	Try to process the queued mail. If the time is given, `sendmail` repeatedly runs through the queue at the specified interval to deliver queued mail; otherwise, it runs only once.
`-qXstring`	Run the queue once, limiting the jobs to those matching `Xstring`; the letter `X` can be:
	`I`	Limit based on queue indentifier (see `-M`).
	`x`	Limit based on the recipient (see `-R`).
	`S`	Limit based on the sender.
`-Rstring`	Attempt to deliver any message with a recipient containing `string`.
`-t`	Read the header for `To:`, `Cc:`, and `Bcc:` lines, and send to everyone listed in the header. The `Bcc:` line is deleted before sending. Any names in the argument vector are deleted from the send list.
`-v`	Use verbose mode.
`-Xlogfile`	Log all traffic in and out of `sendmail` in the indicated `logfile`.

"sendmail Configuration Options" describes the options.

You can specify several configuration options as primitive flags. These are the -c, -e, -i, -m, -T, and -v arguments. Also, you can specify the -f configuration option as the -s argument.

`sendmail` Configuration Options

You can set the options shown in Table B-2 using the -o flag on the command line or the O line in the configuration file.

Table B-2 sendmail Configuration Options


Option		Description
`-Afile`		Use the named `file` as the alias file instead of `/etc/mail/aliases`. If no file is specified, use aliases in the current directory.
`-atime`		Wait a set amount of time (in minutes) for an `@:@` entry to exist in the alias database before starting. If it does not appear after that time, rebuild the database.
`-Bvalue`		Blank substitute. Default is the dot (.) character.
`-bn`		Disallow empty messages to more than `n` recipients.
`-Cn`		Check after `n` recipients.
`-c`		If an outgoing mailer is marked as being expensive, do not connect immediately. A queue process must be run to actually send the mail.
`-D`		If set, rebuild the alias database if necessary and possible. If this option is not set, `sendmail` never rebuilds the alias database unless explicitly requested with `-bi`.
`-dx`		Deliver in mode `x`. Legal modes are:
	`i`		Deliver interactively (synchronously).
	`b`		Deliver in background (asynchronously).
	`q`		Queue the message (deliver during queue run).
`-Estring`		Append error messages with `string`; if `string` starts with a slash, it is assumed to be the path name of a file containing a message.
`-ex`		Dispose of errors, using mode `x`. The values for `x` are:
	`p`		Print error messages (default).
	`q`		No messages, just give exit status.
	`m`		Mail back errors to sender.
	`w`		Write back errors (mail if user not logged in).
	`e`		Mail back errors and always give zero exit status.
`-Fn`		The temporary queue file mode, in octal. Values of `644` and `600` are good choices for `n`.
`-f`		Save UNIX-style `From` lines at the front of headers; normally they are assumed to be redundant and discarded.
`-gn`		Set the default group ID for mailers to run in to `n`.
`-Hfile`		Specify the help file for SMTP [Postel 82].
`-hn`		Set maximum hop count to n.
`-I`		Insist that the name server be running to resolve host requests.
`-i`		Ignore dots in incoming messages.
`-Jpath`		Set the path for searching for users `.forward` files.
`-j`		Send error messages in MIME format.
`-Ktimeout`		Set the maximum amount of time a cached connection will be permitted to be idle.
`-kn`		Select the maximum number of open connections that will be cached at a time. The default is 1.
`-Ln`		Set the default log level to n.
`-l`		If there is an `Errors-To:` header, send the error messages to the addresses listed there.
`-Mxvalue`		Set the macro `x` to `value`; this is intended only for use from the command line.
`-m`		Send to the sender also, even if the sender is in an alias expansion.
`-n`		Validate the RHS of aliases when rebuilding the aliases database.
`-Ooptions`		Set server SMTP options. The options are `key`=`value` pairs. The `key` can be:
	`Addr`		Address mask (the default value is INADDR_ANY).
	`Family`		Address family (the default value is INET).
	`Listen`		Size of listen queue (the default value is 10).
	`Port`		Name or number of the listening port (the default value is smtp).
`-o`		Assume that the headers may be in old format; that is, spaces delimit names. This flag actually turns on an adaptive algorithm: If any recipient name contains a comma, parenthesis, or angle bracket, it is assumed that commas already exist. If this flag is not on, only commas delimit names. Headers are always output with commas between the names.
`-Pname`		Send the header from error messages from the `MAILER-DAEMON` to this name (which is the local postmaster).
`-popt,opt`		Set privacy options. The value for `opt` can be:
	`authwarnings`		Put X-Authentication-Warning: headers in messages.
	`goaway`		Disallow 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.
	`novrfy`		Disallow VRFY.
	`public`		Allow open access.
	`restrictmailq`		Restrict `mailq` command.
	`restrictqrun`		Restrict -q command line flag to root and the owner of the queue.
`-Qdir`		Use the named `dir` as the queue directory.
`-qfactor`		Use factor as the multipler in the map function to decide when to just queue up jobs rather than run them; defaults to 600000.
`-R`		If the mailbox is mounted from a remote server, send any outgoing mail through that server.
`-rtimeouts`		Timeout reads after an interval.The timeouts argument is a list of `keyword=value` pairs`.`The recognized timeouts, their default and minimum values are:
	`command`		Command read [1h, 3m].
	`datablock`		Data block read [1h, 3m].
	`datafinal`		Reply to a final "." in data [1h, 10m].
	`datainit`		Reply to DATA command [5m, 2m].
	`helo`		Reply to HELO or EHLO commands [5m, none].
	`ident`		IDENT protocol timeout [30s, none].
	`initial`		Wait for initial greeting message [5m, 5m].
	`mail`		Reply to MAIL command [10m, 5m].
	`misc`		Reply to NOOP or VERB commands [2m, none].
	`quit`		Reply to QUIT command [2m, none].
	`rcpt`		Reply to RCPT command [1h, 5m].
	`rset`		Reply to RSET command [5m, none].
`-Sfile`		Save statistics in the named `file`.
`-s`		Always initiate the queue file, even if you are going to try immediate delivery. `sendmail` always initiates the queue file before returning control to the client under any circumstance.
`-Trtime/wtime`		Set the queue timeout to `rtime`. After this interval, messages that have not been successfully sent are returned to the sender. The `wtime` variable is optional and selects the time after which a warning message is sent.
`-ttzinfo`		Set the time zone.
`-un`		Set the default user ID for mailers to `n`. Mailers without the `-S` flag in the mailer definition are run as this user.
`-Vfallbackhost`		Select `fallbackhost` to act like a low priority MX on every host.
`-v`		Run in verbose mode.
`-w`		Connect directly to a host as though it has no MX records at all. This option is not recommended.
`-Xn`		Set the load average value, so that the `sendmail` daemon refuses incoming SMTP connections when the system is overloaded to reduce system load. The default is 12; 0 disables this feature.
`-xn`		Set the load average value so that `sendmail` simply queues mail (regardless of the `-dx`option) to reduce system load. Default is 8; 0 disables this feature.
`-Y`		Deliver each job that is run from the queue in a separate process.
`-yfactor`		The `factor` is added to the priority for each recipient (thus lowering the priority of the job for messages with many recipients). The default is 30000.
`-Zfactor`		The `factor` is added to the priority for each recipient (thus lowering the priority of the job for messages with many recipients). The default is 90000.
`-zfactor`		The `factor` is added to the priority every time a job is processed. The default is 1800.
`-7`		Strip input to 7 bits for compatibility with old systems.
`-\|`		Consider group writable `:include:` and `.forward` files as unsafe, so that entries in these files cannot reference programs or write directly to files.

Mailer Flags

Table B-3 describes the flags that you can set in the mailer description.

Table B-3 sendmail Flags Set in the Mailer Description


Flag	Description
`-a`	Run Extended SMTP protocol.
`-b`	Force a blank line at the end of a message.
`-C`	Append the `@domain` clause from the sender to any names in the header that do not have an at sign (`@`) after being rewritten by rule set 3. This option is not recommended. This flag allows mail with headers with this form:
	`From:` `user1@local` `To:` `user2,` `user3@remote`
	to be automatically rewritten as:
	`From:` `user1@local` `To:` `user2@local,` `user3@remote`
`-c`	Do not include comments in addresses.
`-D`	Look for a `Date:` header line.
`-E`	Escape `From` lines to be `>From` (usually specified with `-U`).
`-e`	Avoid connecting to this mailer, which is expensive, normally; any necessary connection occurs during a queue run.
`-F`	Look for a `From:` header line.
`-f`	Look for an `-f` `from` flag, but only if this is a network forward operation (that is, the mailer gives an error if the executing user does not have special permissions).
`-g`	Send error messages from the `MAILER-DAEMON` instead of using the null return address.
`-h`	Preserve uppercase in host names for this mailer.
`-I`	Select SMTP when contacting another `sendmail`.
`-L`	Limit the line lengths as specified in RFC 821.
`-l`	Perform final delivery because this mailer is local.
`-M`	Look for a `Message-Id:` header line.
`-m`	Enable the mailer to send a message to multiple users on the same host in one transaction. When a `$u` macro occurs in the `argv` part of the mailer definition, that field is repeated as necessary for all qualifying users. The `L=` field of the mailer description can be used to limit the total length of the `$u` expansion.
`-n`	Do not insert a UNIX-style `From` line on the front of the message.
`-P`	Look for a `Return-Path:` line.
`-p`	Always add local host name to the `MAIL From:` line of SMTP, even if there already is one.
`-r`	Send an `-r` flag. Performs the same function as `-f`.
`-S`	Do not reset the user ID before calling the mailer. This flag would be used in a secure environment where `sendmail` ran as `root`. This flag could be used to avoid forged names.
`-s`	Strip quote characters from the name before calling the mailer.
`-U`	Look for UNIX-style `From` lines with the UUCP-style `remote from` `<host>` on the end.
`-u`	Preserve uppercase in user names for this mailer.
`-X`	Use the hidden dot algorithm as specified in RFC 821; basically, any line beginning with a dot will have an extra dot appended (to be stripped at the other end). This flag ensures that lines in the message containing a dot do not terminate the message prematurely.
`-x`	Look for a `Full-Name:` header line.
`-7`	Strip output to 7 bits.

Appendix B sendmail Options

sendmail Command-Line Arguments

sendmail Configuration Options

Mailer Flags

Appendix B `sendmail` Options

`sendmail` Command-Line Arguments

`sendmail` Configuration Options