"Scott W. Sander" writes:

Received: from mail.domain.test by appserver4.domain.com (Dovecot) with LMTP id z7RGLzH4uldlPAAAxdv4Dw for <user@domain.test>; Mon, 22 Aug 2016 09:03:45 -0400

I want the part that says "by appserver4.domain.com (Dovecot)" to say "by mail.domain.test (Dovecot)". I don't want it to say the FQDN of the actual host server that is running Dovecot.

The server currently referenced as "mail.domain.test" in the headers is postfix running on the same machine.

Oh yeah, right, LMTP. I don't run LMTP myself, but I suspect the hostname is mapped from the IP of the LMTP listening interface (using /etc/hosts or DNS). Maybe you can change the IP of your listening interface to match mail.domain.test and firewall it off if that IP is public facing.

From reading the code, I can't quite grok how LMTP derives the host label, but as a last resort, you can patch at src/lmtp/commands.c in client_get_added_headers().

Joseph Tam <jtam.home@gmail.com>