On Tue, Aug 25, 2015 at 10:24:48AM -0400, Wietse Venema wrote: > Hans Ginzel: > > On Tue, Aug 25, 2015 at 09:51:50AM -0400, Wietse Venema wrote: > > >Based on the tiny bits of information revealed sofar, I suggest > > >using non_smtpd_milters. > > > > Thank you. > > If you need to rewrite headers in remote email, then you can achieve > that with smtpd_milters. > > Milters receive the message content after Postfix has processed it, > including From: and other headers that were added by Postfix itself.
It is also possible to introduce a "null" content-filter hop, and then use either smtp_header_checks or header_checks via the reinjection smtpd/cleanup service. By a "null" content-filter I mean a configuration in which the content_filter setting reinjects mail right back into Postfix (at some loopback SMTP port othat than 25) without actually doing any filtering (beyond smtp_header_checks and the like). -- Viktor.