NAME
bounce - Postfix bounce message template format
SYNOPSIS
bounce_template_file = /etc/postfix/bounce.cf
postconf -b [template_file]
DESCRIPTION
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.
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_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 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 $myhostname.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
EOF
The usage and specification of bounce templates is subject to the following
restrictions:
- •
- No special meaning is given to the backslash character or
to leading whitespace; these are always taken literally.
- •
- Inside the << context, the "$" character is
special. To produce a "$" character as output, specify
"$$".
- •
- 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:
- •
- 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:".
- •
- Template message headers must not span multiple lines.
- •
- Template message headers do not support $parameter
expansions.
- •
- 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.
- mydomain
- Expands into the value of the mydomain parameter.
With "smtputf8_enable = yes", this replaces ACE labels
(xn--mumble) with their UTF-8 equivalent.
This feature is available in Postfix 3.0.
- myhostname
- Expands into the value of the myhostname parameter.
With "smtputf8_enable = yes", this replaces ACE labels
(xn--mumble) with their UTF-8 equivalent.
This feature is available in Postfix 3.0.
The usage and specification of template message text is subject to the following
restrictions:
- •
- The template message text is not sent in Postmaster copies
of delivery status notifications.
- •
- 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
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA