BOUNCE 5
NAME
bounce
-
Postfix bounce message template format
"SYNOPSIS"
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 delivery 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_template_file configuration parameter. This document describes the general procedure to create a bounce template file, followed by the specific details of bounce template formats.DESCRIPTION
"GENERAL PROCEDURE"
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 the command
postconf -b temporary_fileErrors 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 notification text. Once the result is satisfactory, copy the template to the Postfix configuration directory and specify in main.cf something like:
/etc/postfix/main.cf: 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 verify_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 (template_name = <<'EOF'). Here is an example:
# The failure template is used for undeliverable mail. failure_template = <<EOF Charset: us-ascii 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 EOF
The usage and specification of bounce templates is subject to the following restrictions:
\(bu
No special meaning is given to the backslash character or
to leading whitespace; these are always taken literally.
\(bu
Inside the << context, the "$" character is special. To
produce a "$" character as output, specify "$$".
\(bu
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. Some become message headers in the delivery status notification; some control the formatting of that notification. Headers not specified in a template will be left at their default value. The following headers are supported:
Charset:
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 notification.
Subject:
The subject in the message header of the delivery status
notification that is returned to the sender.
Postmaster-Subject:
The subject that will be used in Postmaster copies of
undeliverable 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:
\(bu
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:".
\(bu
Template message headers must not span multiple lines.
\(bu
Template message headers do not support $parameter expansions.
\(bu
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.
delay_warning_time_suffix
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.
maximal_queue_lifetime_suffix
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 following restrictions:
\(bu
The template message text is not sent in Postmaster copies
of delivery status notifications.
\(bu
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 template when it sends a delivery status
notification.
"SEE ALSO"
bounce(8), Postfix delivery status notifications postconf(5), configuration parameters"LICENSE"The Secure Mailer license must be distributed with this software."HISTORY"The Postfix bounce template format was originally developed by Nicolas Riendeau."AUTHOR(S)"Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA