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Postfix Documentation
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Debugging your address manipulations

With Postfix version 2.1 and later you can ask Postfix to produce mail delivery reports for debugging purposes. These reports not only show sender/recipient addresses after address rewriting and alias expansion or forwarding, they also show information about delivery to mailbox, delivery to non-Postfix command, responses from remote SMTP servers, and so on.

Postfix can produce two types of mail delivery reports for debugging:

  • What-if: report what would happen, but do not actually deliver mail. This mode of operation is requested with:

    $ /usr/sbin/sendmail -bv address...
    Mail Delivery Status Report will be mailed to <your login name>.
  • What happened: deliver mail and report successes and/or failures, including replies from remote SMTP servers. This mode of operation is requested with:

    $ /usr/sbin/sendmail -v address...
    Mail Delivery Status Report will be mailed to <your login name>.

These reports contain information that is generated by Postfix delivery agents. Since these run as daemon processes and do not interact with users directly, the result is sent as mail to the sender of the test message. The format of these reports is practically identical to that of ordinary non-delivery notifications.

As an example, below is the delivery report that is produced with the command "sendmail -bv [email protected]". The first part of the report contains human-readable text. In this case, mail would be delivered via, and the SMTP server replies with "250 Ok". Other reports may show delivery to mailbox, or delivery to non-Postfix command.

Content-Description: Notification
Content-Type: text/plain

This is the Postfix program at host

Enclosed is the mail delivery report that you requested.

                        The Postfix program

<[email protected]>: delivery via[]: 250 Ok

The second part of the report is in machine-readable form, and includes the following information:

  • The envelope sender address ([email protected]).
  • The envelope recipient address ([email protected]). If the recipient address was changed by Postfix then Postfix also includes the original recipient address.
  • The delivery status.

Some details depend on Postfix version. The example below is for Postfix version 2.3 and later.

Content-Description: Delivery report
Content-Type: message/delivery-status

Reporting-MTA: dns;
X-Postfix-Queue-ID: 84863BC0E5
X-Postfix-Sender: rfc822; [email protected]
Arrival-Date: Tue, 13 Apr 2004 19:27:43 -0400 (EDT)

Final-Recipient: rfc822; [email protected]
Action: deliverable
Status: 2.0.0
Remote-MTA: dns;
Diagnostic-Code: smtp; 250 Ok

The third part of the report contains the message that Postfix would have delivered, including From: and To: message headers, so that you can see any effects of address rewriting on those. Mail submitted with "sendmail -bv" has no body content so none is shown in the example below.

Content-Description: Message
Content-Type: message/rfc822

Received: by (Postfix, from userid 1001)
        id 84863BC0E5; Tue, 13 Apr 2004 19:27:43 -0400 (EDT)
Subject: probe
To: [email protected]
Message-Id: <[email protected]>
Date: Tue, 13 Apr 2004 19:27:43 -0400 (EDT)
From: [email protected] (Wietse Venema)
Postfix Documentation
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