Eduardo Maia: > Hi, > > I need to block emails with fake FROM like : > > From: "Nick Blue <n...@domain.pt>" <yk...@omega-eng.co.jp> > > > The postfix has the feature header_checks and mime_header_checks. When > the FROM is with plain text, it works fine, but when the FROM is mime > encoded like this: > > From: =?UTF-8?B?PElQQlJJQ0sgbsK6IDMyNTc0PiBhc2FudG9zQGlwYnJpY2suY29t?= > <alcal...@ayuntamientocamaleno.com> > > the email is not blocked, even with mime_header_checks.
You are going to need a Milter or other kind of content filter to do this. Postfix has no built-in content manipulation language. https://github.com/mikenye/milter-decode-headers This actually inserts decoded headers X-Decoded-From: X-Decoded-From-Encoding: And similar for Subject: headers if you want to decode those, too You should IGNORE those inserted headers for mail that is not rejected: milter_header_checkds configuration: IF /^X-Decoded-From/ /^X-Decoded-From: some evil pattern/ REJECT # Ignore X-Decoded-From: and X-Decoded-From-Encoding: . IGNORE ENDIF And similar for Subject: headers if you want to decode those, too DO NOT put whitespace before text inside IF and ENDIF. Wietse
