Forum mail failure: Reason found, please fix

Here’s the error log:
[java]Sep 10 17:34:57 5 postfix/smtpd[25474]: connect from static.68.68.76.144.clients.your-server.de[144.76.68.68]
Sep 10 17:34:57 5 postfix/smtpd[25474]: NOQUEUE: reject: RCPT from static.68.68.76.144.clients.your-server.de[144.76.68.68]: 450 4.7.1 <Ubuntu-1204-precise-64-minimal>: Helo command rejected: Host not found; from=<www-data@hub.jmonkeyengine.org> to=<toolforger@durchholz.org> proto=ESMTP helo=<Ubuntu-1204-precise-64-minimal>
Sep 10 17:34:59 5 postfix/smtpd[25474]: lost connection after RSET from static.68.68.76.144.clients.your-server.de[144.76.68.68]
Sep 10 17:34:59 5 postfix/smtpd[25474]: disconnect from static.68.68.76.144.clients.your-server.de[144.76.68.68][/java]

What’s happening is that hub.monkeyengine.org is identifying itself as “Ubuntu-1204-precise-64-minimal”, which does not match any of 144.76.68.68’s DNS names, so the receiving mail server rejects the connection.

Unless that Postfix configuration is absolutely nonstandard, /etc/postfix/main.cf should be saying something along these lines:
[java]mydomain = jmonkeyengine.org
myhostname = hub.jmonkeyengine.org[/java]
(The docs say that mydomain and myhostname should be different, but this applies to setups where the mail server is separate from the other machine(s) serving for the domain; the two settings could be identical in that single-server setup.)

2 Likes

Hmm, interesting find. What’s the verdict @sbook ?

Weird, how come I’m getting the email then?

In any case, I’ve updated the server configuration and restarted Postfix, thanks @toolforger (did you get this email? how about you @erlend_sh?)

I got about 150 forum mails that had been waiting in the outbound queue of hub.jmonkeyengine.org :lol:

@sbook you probably have been getting mail because the accepting mail server didn’t care about domain name mismatches in HELO/EHLO commands. It’s essentially a policy thing - MOST mail servers do this check but not all.

@toolforger said: I got about 150 forum mails that had been waiting in the outbound queue of hub.jmonkeyengine.org :lol:

@sbook you probably have been getting mail because the accepting mail server didn’t care about domain name mismatches in HELO/EHLO commands. It’s essentially a policy thing - MOST mail servers do this check but not all.

oooooops :smiley: well… I guess email is working now. Thanks again for tracking that down

Heh. No problem. I asked for these mails after all :slight_smile:

I’m surprised people aren’t complaining. I sure have read complaints from people not receiving notifications.
Given that usually at least one person complains about whatever has changed, it’s possible that forum notifications are delayed for other reasons.

Have you tried the mailq command? It displays the content of the current outbound queue.

Wow, thanks a lot for this fix! We’ve known something was up for quite some time, but since we usually got our e-mail notifications when we needed them it never became a pressing issue.