Been trying to figure this out...
I have a new server set up about a month ago, CentOS with virtualmin control panel.
On a shared ip, I have one domain that, when someone tries to mail to it, they get a bounce saying:
Final-recipient: rfc822; (username)@(domainname).org
Diagnostic-Code: smtp; 554 5.7.1 : Relay access denied
and I get a 'Relay access denied' message in the maillog. Like this:
May 24 11:02:55 jessica postfix/smtpd: NOQUEUE: reject: RCPT from qmta04.westchester.pa.mail.comcast.net[126.96.36.199]: 554 5.7.1 <test@(domainname).org>: Relay access denied; from=<chris@(mydomain).com> to=<test@(domainname).org> proto=ESMTP helo=<QMTA04.westchester.pa.mail.comcast.net>
Mail for this domain has been working ok until yesterday.
I've checked the dns (and the connection is making it to the server), it appears ok. My hosting company confirmed dns was good.
All the other domains are receiving mail ok. I don't see anything that I've set differently for this one.
In a "could this be related?"... the shared ip this domain is on was blacklisted on trendmicro's dul list a few days ago. I wrote them and they said the issue was rdns related (getting the rdns pointed to my server was on my list, but I had not done that yet). I wrote back and they removed me from the blacklist, and I contacted my host and the reverse dns is being set.
However, even after being removed from the blacklist (I have confirmed this), I'm still getting the 'relay access denied' message, and just on that one domain. Wouldn't blacklisting affect all the sites on that ip?
Does postfix have access to the blacklist for verification, and would it have caused a block somehow, I had assumed only spamassassin would do that, after the email was accepted. IF postfix does check blacklists, is there a way to have it's cache flushed? I did have postgrey on, but that is disabled right now until I can fix this, just to make sure it wasn't doing anything.
Any suggestions on how to fix this? And what relay would this be blocking anyway? Postfix to - ?