> On Nov 22, 2016, at 3:02 AM, Gerben Wierda <[email protected]> wrote: > > I was wondering, how many legitimate email (i.e. poorly configured but legit > MTA’s out there) would be blocked with either of these? > > unknown_client_reject_code = 550 # Hmm, should this be another value in the > 5xx range? > smtpd_recipient_restrictions = > …, > reject_unknown_client_hostname
I tried warn_if_reject reject_unknown_client_hostname, for a while and found far too much legitimate mail was triggering the warning. > I personally suspect that the reject_unknown_client_hostname would block too > much, but the reject_unknown_helo_hostname would be ok. Am I right? No. Try something like this: grep helo /var/log/maillog | egrep -v reject | grep -o "helo.*$" | sort -u
