Postfix Address Verification
seamus at rheelweb.co.nz
Fri Jun 29 04:57:31 IST 2007
Drew Marshall wrote:
> On Wed, June 27, 2007 23:46, Seamus Allan wrote:
>> It seems after implementing this that I am having a lot of spam stopped
>> at MTA level - this is very good.<br>
>> However, the next morning I came in to discover that some of the
>> domains we host were not getting any email.<br>
>> I used telnet to pretend to have a fake session with the smtp server,
>> and interestingly, when trying to do a rcpt <a
>> href="mailto:to:user at brokendomain.com">to:user at brokendomain.com</a>, I
>> get the following error message.<br>
>> 450 <a class="moz-txt-link-rfc2396E"
>> href="mailto:user at brokendomain.com"><user at brokendomain.com></a>:
>> Recipient address rejected: Domain
>> not found<br>
>> Why is this happening? How come that Postfix is able to look into the
>> transport map and check the next server in line to see whether the user
>> is valid for most of the domains, but not for some. Is there a
>> misconfiguration somewhere? Is the verify map full or something?<br>
> Firstly, please could you not use HTML mail. It does become something of a
> mess (As you can see above) when working in plain text.
I even made a point of not top posting. Guess I can't make *everyone* happy.
> Anyway, check your maillog as I would expect the domain not found error to
> come from a Postfix client access restriction (Reject unknown sender
> domain for example) and nothing to do with your recipient maps. The logs
> will tell you more.
I spent the good part of a day investigating logs and found almost
nothing useful. I was expecting to see a point where the main (hub)
mailserver started rejecting the (Mailscanner) Gateways probes to check
whether a mailbox existed, as the probes are only Helo, Mail from, rcpt
to, then a disconnect.
Anywho, here are some log snippets for you to gander at.
This is for a domain where is worked:
Jun 28 02:49:24 gatekeeper2 postfix/smtpd: NOQUEUE: reject: RCPT
from c175-80.icpnet.pl[184.108.40.206]: 550 <user at validdomain.com>:
Recipient address rejected: undeliverable address: host
192.168.1.225[192.168.1.225] said: 550 Requested action not taken:
mailbox unavailable or not local (in reply to RCPT TO command);
from=<agassy at gopitts.com> to=<user at validdomain.com> proto=SMTP
And this is for one where is didn't:
Jun 28 02:49:28 gatekeeper2 postfix/smtpd: NOQUEUE: reject: RCPT
from unknown[220.127.116.11]: 450 <user at validdomain.com>: Recipient address
rejected: Domain not found; from=<jahka at place.com>
to=<user at validdomain.com> proto=ESMTP helo=<aram.chello.hu>
After scouring the logs on both the gateway machine and the mail hub and
can't seem to find anything useful.
Rheel Electronics Ltd
Phone +64-3-386 3070 Fax +64-3-386-3071
seamus at rheelweb.co.nz
This e-mail together with any attachments is confidential, may be
subject to legal privilege and may contain proprietary information,
including information protected by copyright. If you are not the
intended recipient, please do not copy, use or disclose this e-mail;
please notify us immediately by return e-mail and then delete this e-mail.
More information about the MailScanner