I get asked day by day to verify if a mail was successfully sent out by our server (because client complains that he sent it to xy and his recipient never got it). Most likely this isn't our fault but the recipients mail server dropped/flagged the mail as spam. So my question is how to verify (if it's possible) that a mail was SENT OUT by postfix from our end?
If I grepping through the mail.log.* files I get entries like:
Sep 14 06:27:10 mailhost postfix/qmgr: 14B40C65A1: from=<email@example.com>, size=1372, nrcpt=1 (queue active) Sep 14 06:27:10 mailhost postfix/qmgr: 11673C5FDA: from=<firstname.lastname@example.org>, size=1469, nrcpt=1 (queue active)
This information is completely invaluable. By this all I see is that email@example.com sent an email at 6:27 to somebody and it was queued by the mail system (not that it was sent out and what happend after).
Is it possible to log these events with postfix? Even if it takes increasing the error log I need this information.