BOUNCE(5) File Formats Manual BOUNCE(5)
bounce - Postfix bounce message template format
bounce_template_file = /etc/postfix/bounce.cf
postconf -b [template_file]
The Postfix bounce(8) server produces delivery status notification
(DSN) messages for undeliverable mail, delayed mail, successful deliv-
ery or address verification requests.
By default, these notifications are generated from built-in templates
with message headers and message text. Sites can override the built-in
information by specifying a bounce template file with the bounce_tem-
plate_file configuration parameter.
This document describes the general procedure to create a bounce tem-
plate file, followed by the specific details of bounce template for-
To create a customized bounce template file, create a temporary copy of
the file /etc/postfix/bounce.cf.default and edit the temporary file.
To preview the results of $name expansions in the template text, use
postconf -b temporary_file
Errors in the template will be reported to the standard error stream
and to the syslog daemon.
While previewing the text, be sure to pay particular attention to the
expansion of time value parameters that appear in the delayed mail
Once the result is satisfactory, copy the template to the Postfix con-
figuration directory and specify in main.cf something like:
bounce_template_file = /etc/postfix/bounce.cf
TEMPLATE FILE FORMAT
The template file can specify templates for failed mail, delayed mail,
successful delivery or for address verification. These templates are
named failure_template, delay_template, success_template and ver-
ify_template, respectively. You can but do not have to specify all
four templates in a bounce template file.
Each template starts with "template_name = <<<<EOF" and ends with a line
that contains the word "EOF" only. You can change the word EOF, but you
can't enclose it in quotes as with the shell or with Perl (tem-
plate_name = <<<<'EOF'). Here is an example:
# The failure template is used for undeliverable mail.
failure_template = <<EOF
From: MAILER-DAEMON (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
Postmaster-Subject: Postmaster Copy: Undelivered Mail
This is the mail system at host $myhostname.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
The usage and specification of bounce templates is subject to the fol-
o No special meaning is given to the backslash character or to
leading whitespace; these are always taken literally.
o Inside the << context, the "$" character is special. To produce
a "$" character as output, specify "$$".
o Outside the << context, lines beginning with "#" are ignored, as
are empty lines, and lines consisting of whitespace only.
Examples of all templates can be found in the file bounce.cf.default in
the Postfix configuration directory.
TEMPLATE HEADER FORMAT
The first portion of a bounce template consists of optional template
headers. These either become message headers in the delivery status
notification, or control the formatting of the notification. Headers
not specified in a template will be left at their default value.
The following headers are supported:
The MIME character set of the template message text. See the
"TEMPLATE MESSAGE TEXT FORMAT" description below.
From: The sender address in the message header of the delivery status
The subject in the message header of the delivery status notifi-
The subject that will be used in Postmaster copies of undeliver-
able or delayed mail notifications. These copies are sent under
control of the notify_classes configuration parameter.
The usage and specification of template message headers is subject to
the following restrictions:
o Template message header names can be specified in upper case,
lower case or mixed case. Postfix always produces bounce message
header labels of the form "From:" and "Subject:".
o Template message headers must not span multiple lines.
o Template message headers do not support $parameter expansions.
o Template message headers must contain ASCII characters only, and
must not contain ASCII null characters.
TEMPLATE MESSAGE TEXT FORMAT
The second portion of a bounce template consists of message text. As
the above example shows, template message text may contain main.cf
$parameters. Besides the parameters that are defined in main.cf, the
following parameters are treated specially depending on the suffix that
is appended to their name.
Expands into the value of the delay_warning_time parameter,
expressed in the time unit specified by suffix, which is one of
seconds, minutes, hours, days, or weeks.
Expands into the value of the maximal_queue_lifetime parameter,
expressed in the time unit specified by suffix. See above under
delay_warning_time for possible suffix values.
The usage and specification of template message text is subject to the
o The template message text is not sent in Postmaster copies of
delivery status notifications.
o If the template message text contains non-ASCII characters,
Postfix requires that the Charset: template header is updated.
Specify an appropriate superset of US-ASCII. A superset is
needed because Postfix appends ASCII text after the message tem-
plate when it sends a delivery status notification.
bounce(8), Postfix delivery status notifications
postconf(5), configuration parameters
The Secure Mailer license must be distributed with this software.
The Postfix bounce template format was originally developed by Nicolas
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA