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SENDMAIL(1) General Commands Manual SENDMAIL(1)


sendmail – Postfix to Sendmail compatibility interface


sendmail [option …] [recipient …]

sendmail -bp

sendmail -I


The Postfix sendmail command implements the Postfix to Sendmail com‐
patibility interface. For the sake of compatibility with existing
applications, some Sendmail command-line options are recognized but
silently ignored.

By default, Postfix sendmail reads a message from standard input
until EOF or until it reads a line with only a . character, and
arranges for delivery. Postfix sendmail relies on the postdrop
command to create a queue file in the maildrop directory.

Specific command aliases are provided for other common modes of opera‐

mailq List the mail queue. Each entry shows the queue file ID, message
size, arrival time, sender, and the recipients that still need
to be delivered. If mail could not be delivered upon the last
attempt, the reason for failure is shown. The queue ID string is
followed by an optional status character:

* The message is in the active queue, i.e. the message is
selected for delivery.

! The message is in the hold queue, i.e. no further deliv‐
ery attempt will be made until the mail is taken off

This mode of operation is implemented by executing the
postqueue command.

Initialize the alias database. If no input file is specified
(with the -oA option, see below), the program processes the
file(s) specified with the alias_database configuration parame‐
ter. If no alias database type is specified, the program uses
the type specified with the default_database_type configuration
parameter. This mode of operation is implemented by running the
postalias command.

Note: it may take a minute or so before an alias database update
becomes visible. Use the “postfix reload” command to eliminate
this delay.

These and other features can be selected by specifying the appropriate
combination of command-line options. Some features are controlled by
parameters in the configuration file.

The following options are recognized:

-Am (ignored)

-Ac (ignored)
Postfix sendmail uses the same configuration file regardless of
whether or not a message is an initial submission.

-B body_type
The message body MIME type: 7BIT or 8BITMIME.

-bd Go into daemon mode. This mode of operation is implemented by
executing the “postfix start” command.

-bh (ignored)

-bH (ignored)
Postfix has no persistent host status database.

-bi Initialize alias database. See the newaliases command above.

-bl Go into daemon mode. To accept only local connections as with
Sendmail´s -bl option, specify “inet_interfaces = loopback” in
the Postfix configuration file.

-bm Read mail from standard input and arrange for delivery. This is
the default mode of operation.

-bp List the mail queue. See the mailq command above.

-bs Stand-alone SMTP server mode. Read SMTP commands from standard
input, and write responses to standard output. In stand-alone
SMTP server mode, mail relaying and other access controls are
disabled by default. To enable them, run the process as the
mail_owner user.

This mode of operation is implemented by running the smtpd(8)

-bv Do not collect or deliver a message. Instead, send an email
report after verifying each recipient address. This is useful
for testing address rewriting and routing configurations.

This feature is available in Postfix version 2.1 and later.

-C config_file

-C config_dir
The path name of the Postfix file, or of its parent
directory. This information is ignored with Postfix versions
before 2.3.

With all Postfix versions, you can specify a directory pathname
with the MAIL_CONFIG environment variable to override the loca‐
tion of configuration files.

-F full_name
Set the sender full name. This overrides the NAME environment
variable, and is used only with messages that have no From: mes‐
sage header.

-f sender
Set the envelope sender address. This is the address where
delivery problems are sent to. With Postfix versions before 2.1,
the Errors-To: message header overrides the error return

-G Gateway (relay) submission, as opposed to initial user submis‐
sion. Either do not rewrite addresses at all, or update incom‐
plete addresses with the domain information specified with

This option is ignored before Postfix version 2.3.

-h hop_count (ignored)
Hop count limit. Use the hopcount_limit configuration parameter

-I Initialize alias database. See the newaliases command above.

-i When reading a message from standard input, don´t treat a line
with only a . character as the end of input.

-L label (ignored)
The logging label. Use the syslog_name configuration parameter

-m (ignored)
Backwards compatibility.

-N dsn (default: ‘delay, failure’)
Delivery status notification control. Specify either a
comma-separated list with one or more of failure (send notifica‐
tion when delivery fails), delay (send notification when deliv‐
ery is delayed), or success (send notification when the message
is delivered); or specify never (don’t send any notifications at

This feature is available in Postfix 2.3 and later.

-n (ignored)
Backwards compatibility.

Non-default alias database. Specify pathname or type:pathname.
See postalias for details.

-O option=value (ignored)
Set the named option to value. Use the equivalent configuration
parameter in instead.

-o7 (ignored)

-o8 (ignored)
To send 8-bit or binary content, use an appropriate MIME encap‐
sulation and specify the appropriate -B command-line option.

-oi When reading a message from standard input, don´t treat a line
with only a . character as the end of input.

-om (ignored)
The sender is never eliminated from alias etc. expansions.

-o x value (ignored)
Set option x to value. Use the equivalent configuration parame‐
ter in instead.

-r sender
Set the envelope sender address. This is the address where
delivery problems are sent to. With Postfix versions before 2.1,
the Errors-To: message header overrides the error return

-R return
Delivery status notification control. Specify “hdrs” to return
only the header when a message bounces, “full” to return a full
copy (the default behavior).

The -R option specifies an upper bound; Postfix will return only
the header, when a full copy would exceed the bounce_size_limit

This option is ignored before Postfix version 2.10.

-q Attempt to deliver all queued mail. This is implemented by exe‐
cuting the postqueue command.

Warning: flushing undeliverable mail frequently will result in
poor delivery performance of all other mail.

-qinterval (ignored)
The interval between queue runs. Use the queue_run_delay config‐
uration parameter instead.

Schedule immediate delivery of mail with the specified queue ID.
This option is implemented by executing the postqueue com‐
mand, and is available with Postfix version 2.4 and later.

Schedule immediate delivery of all mail that is queued for the
named site. This option accepts only site names that are eligi‐
ble for the “fast flush” service, and is implemented by execut‐
ing the postqueue command. See flush(8) for more information
about the “fast flush” service.

This command is not implemented. Use the slower “sendmail -q”
command instead.

-t Extract recipients from message headers. These are added to any
recipients specified on the command line.

With Postfix versions prior to 2.1, this option requires that no
recipient addresses are specified on the command line.

-U (ignored)
Initial user submission.

-V envid
Specify the envelope ID for notification by servers that support

This feature is available in Postfix 2.3 and later.

-XV (Postfix 2.2 and earlier: -V)
Variable Envelope Return Path. Given an envelope sender address
of the form owner-listname@origin, each recipient user@domain
receives mail with a personalized envelope sender address.

By default, the personalized envelope sender address is
owner-listname+user=domain@origin. The default + and = charac‐
ters are configurable with the default_verp_delimiters configu‐
ration parameter.

-XVxy (Postfix 2.2 and earlier: -Vxy)
As -XV, but uses x and y as the VERP delimiter characters,
instead of the characters specified with the default_verp_delim‐
iters configuration parameter.

-v Send an email report of the first delivery attempt (Postfix ver‐
sions 2.1 and later). Mail delivery always happens in the back‐
ground. When multiple -v options are given, enable verbose log‐
ging for debugging purposes.

-X log_file (ignored)
Log mailer traffic. Use the debug_peer_list and debug_peer_level
configuration parameters instead.

By design, this program is not set-user (or group) id. However, it must
handle data from untrusted, possibly remote, users. Thus, the usual
precautions need to be taken against malicious inputs.

Problems are logged to syslogd(8) and to the standard error stream.

Directory with Postfix configuration files.

MAIL_VERBOSE (value does not matter)
Enable verbose logging for debugging purposes.

MAIL_DEBUG (value does not matter)
Enable debugging with an external command, as specified with the
debugger_command configuration parameter.

NAME The sender full name. This is used only with messages that have
no From: message header. See also the -F option above.



The following parameters are especially relevant to this pro‐
gram. The text below provides only a parameter summary. See post‐
conf(5) for more details including examples.

Available with Postfix 2.9 and later:

sendmail_fix_line_endings (always)
Controls how the Postfix sendmail command converts email message
line endings from into UNIX format ().

The DEBUG_README file gives examples of how to trouble shoot a Postfix

debugger_command (empty)
The external command to execute when a Postfix daemon program is
invoked with the -D option.

debug_peer_level (2)
The increment in verbose logging level when a remote client or
server matches a pattern in the debug_peer_list parameter.

debug_peer_list (empty)
Optional list of remote client or server hostname or network
address patterns that cause the verbose logging level to
increase by the amount specified in $debug_peer_level.

Available in Postfix version 2.2 and later:

authorized_flush_users (static:anyone)
List of users who are authorized to flush the queue.

authorized_mailq_users (static:anyone)
List of users who are authorized to view the queue.

authorized_submit_users (static:anyone)
List of users who are authorized to submit mail with the send‐
mail(1) command (and with the privileged postdrop helper com‐

bounce_size_limit (50000)
The maximal amount of original message text that is sent in a
non-delivery notification.

fork_attempts (5)
The maximal number of attempts to fork() a child process.

fork_delay (1s)
The delay between attempts to fork() a child process.

hopcount_limit (50)
The maximal number of Received: message headers that is allowed
in the primary message headers.

queue_run_delay (300s)
The time between deferred queue scans by the queue manager;
prior to Postfix 2.4 the default value was 1000s.

The ETRN_README file describes configuration and operation details for
the Postfix “fast flush” service.

fast_flush_domains ($relay_domains)
Optional list of destinations that are eligible for per-destina‐
tion logfiles with mail that is queued to those destinations.

The VERP_README file describes configuration and operation details of
Postfix support for variable envelope return path addresses.

default_verp_delimiters (+=)
The two default VERP delimiter characters.

verp_delimiter_filter (-=+)
The characters Postfix accepts as VERP delimiter characters on
the Postfix sendmail command line and in SMTP commands.

alias_database (see ‘postconf -d’ output)
The alias databases for local(8) delivery that are updated with
“newaliases” or with “sendmail -bi”.

command_directory (see ‘postconf -d’ output)
The location of all postfix administrative commands.

config_directory (see ‘postconf -d’ output)
The default location of the Postfix and con‐
figuration files.

daemon_directory (see ‘postconf -d’ output)
The directory with Postfix support programs and daemon programs.

default_database_type (see ‘postconf -d’ output)
The default database type for use in newaliases, postalias
and postmap commands.

delay_warning_time (0h)
The time after which the sender receives a copy of the message
headers of mail that is still queued.

mail_owner (postfix)
The UNIX system account that owns the Postfix queue and most
Postfix daemon processes.

queue_directory (see ‘postconf -d’ output)
The location of the Postfix top-level queue directory.

remote_header_rewrite_domain (empty)
Don’t rewrite message headers from remote clients at all when
this parameter is empty; otherwise, rewrite message headers and
append the specified domain name to incomplete addresses.

syslog_facility (mail)
The syslog facility of Postfix logging.

syslog_name (see ‘postconf -d’ output)
The mail system name that is prepended to the process name in
syslog records, so that “smtpd” becomes, for example, “post‐

/var/spool/postfix, mail queue
/etc/postfix, configuration files


pickup(8), mail pickup daemon
qmgr(8), queue manager
smtpd(8), SMTP server
flush(8), fast flush service
postsuper, queue maintenance
postalias, create/update/query alias database
postdrop, mail posting utility
postfix, mail system control
postqueue, mail queue control
syslogd(8), system logging

Use “postconf readme_directory” or “postconf html_directory” to locate
this information.
DEBUG_README, Postfix debugging howto
ETRN_README, Postfix ETRN howto
VERP_README, Postfix VERP howto

The Secure Mailer license must be distributed with this software.

Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA

Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA