I tried using sender_canonical_maps to rewrite sender adresses in envelope & header.
I have amavisd-new setup as a smtpd_proxy_filter. I was able to get rewriting to work for the headers by using: local_header_rewrite_clients = static:all But that's a bit broad, so I tried: local_header_rewrite_clients = 141.42.206.36 to allow rewriting from my mailbox server only. But that simply wouldn't work: Sep 30 17:00:54 mail-ausfall postfix/cleanup[15363]: 995B73DD09: warning: header Subject: Test mit fake adresse from postamt.charite.de[141.42.206.36]; from=<danilo.seid...@cfm-charite.de> to=<hil...@charite.de> proto=ESMTP helo=<postamt.charite.de> -- it would rewrite the envelope, but not the header. mail_version = 2.7-20090828-nonprod -- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebra...@charite.de | http://www.charite.de