I'm using zarafa as MDA with postfix. For privacy reasons I want to filter client internal IP-addresses and stuff like this. To do so I've added the following to master.cf: submission inet n - - - - smtpd [...] -o cleanup_service_name=subcleanup [...] and further down the file: subcleanup unix n - - - 0 cleanup -o header_checks=pcre:/etc/postfix/smtp_header_checks which works perfectly for clients delivering their mail through the submission port. But my zarafa is of course not using the submission port to send mail, hence it doesn't hit the subcleanup routine and outgoing mails contain a very nice X-Mailer: Zarafa-exact_version header which is rather unsatisfying. Is there any way to make zarafa use the subcleanup routine? Any help is much appreciated.