Hello all, I have postfix working pretty well... efficiently blocking a very large amount of spam (very happy with Postfix). But I have a problem... Postfix isn't receiving mail from a specific mail system, and it's critical that it does.
The problem really isn't Postfix. Postfix is doing exactly what it is supposed to do. The mail system in question doesn't always report with the same hostname (it's a web server that sends notification emails, but does not receive email), which means HELO communication and email addresses are seen as bogus. I'm trying to get them to change their setup, but in the mean time, I'm losing email messages that I desperately need. So I'm trying to find a temporary workaround. Example: Apr 3 22:52:06 fs2 postfix/smtpd[32221]: NOQUEUE: reject: RCPT from unknown[x.x.x.x]: 450 <u...@212453-app4.domain.com>: Sender address rejected: Domain not found; from=<u...@212453-app4.domain.com> to=<m...@mydomain.com> proto=ESMTP helo=<212453-app4.domain.com> To be clear, domain.com exists, but 212453-app4.domain.com does not. It contains no host (A) or mail exchanger (MX) record. The IP addresses vary as well (I saw no consistent correlation between the hostname and IP address). In just a few portions of my mail log I see the following hostnames: 212453-app4.domain.com 207113-app1.domain.com 205107-app3.domain.com 207186-app2.domain.com I know, it's goofy... Now, as you can see, my server isn't letting them through (as one would expect). But I need them to be. But I don't want to disable the checks for all mail just so I can receive mail from this remote system. So, my question is... is there a way to let mail from this domain through without turning off the checks (smtpd_sender_restrictions, for example) completely? I tried setting up a pcre lookup table early in the sender restrictions list, but it didn't seem to work (with an "OK" action). Either I did something wrong, or I don't entirely understand how Postfix behaves. Do any of you have any suggestions short of rejecting mail from this mail system?
