For 3.6.2 (from source) may influence this, but I am seeing enough to identify without any change in mail.log:
> Nov 25 18:57:01 mail postfix/smtpd[2814]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 450 4.7.1 <new.internaldomain.mylocal>: Helo command rejected: Host not found; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<new.internaldomain.mylocal> However, adding "debug_peer_list = 127.0.0.1" to main.cf generates a LOT more content, including all responses sent to and from.
