DISCARD(8) System Manager's Manual DISCARD(8)

discard - Postfix discard mail delivery agent

discard [generic Postfix daemon options]


The Postfix discard(8) delivery agent processes delivery requests from the queue manager. Each request specifies a queue file, a sender address, a next-hop destination that is treated as the reason for discarding the mail, and recipient information. The reason may be prefixed with an RFC 3463-compatible detail code. This program expects to be run from the master(8) process manager.

The discard(8) delivery agent pretends to deliver all recipients in the delivery request, logs the "next-hop" destination as the reason for discarding the mail, updates the queue file, and either marks recipients as finished or informs the queue manager that delivery should be tried again at a later time.

Delivery status reports are sent to the trace(8) daemon as appropriate.


The discard(8) mailer is not security-sensitive. It does not talk to the network, and can be run chrooted at fixed low privilege.

RFC 3463 (Enhanced Status Codes)


Problems and transactions are logged to syslogd(8).

Depending on the setting of the notify_classes parameter, the postmaster is notified of bounces and of other trouble.


Changes to main.cf are picked up automatically as discard(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

The default location of the Postfix main.cf and master.cf configuration files.
How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.
The maximal number of digits after the decimal point when logging sub-second delay values.
The sender address of postmaster notifications that are generated by the mail system.
The time limit for sending or receiving information over an internal communication channel.
The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.
The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.
The process ID of a Postfix command or daemon process.
The process name of a Postfix command or daemon process.
The location of the Postfix top-level queue directory.
The syslog facility of Postfix logging.
A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

qmgr(8), queue manager
bounce(8), delivery status reports
error(8), Postfix error delivery agent
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
syslogd(8), system logging


The Secure Mailer license must be distributed with this software.


This service was introduced with Postfix version 2.2.

Victor Duchovni
Morgan Stanley
Based on code by:
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