451 #4.1.3 Domain of sender address does not resolve

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Level 1

105 points

451 #4.1.3 Domain of sender address does not resolve

My mail server does not seem to be able to send to a number of other mail servers (rr.com and gmx.net so far).

This is the error message I get back:
451 #4.1.3 Domain of sender address <sender@domain.com> does not resolve (in reply to MAIL FROM command)
and the status is set to deferred.

Reverse DNS is exactly pointing to mail.domain.com.

Does anyone know, where the problem could be and how to solve it?

Many thanks

Lane

Many Macs, Mac OS X (10.4.8)

Posted on Feb 24, 2007 9:25 AM

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Answer 1

pterobyte

Level 6

11,104 points

Feb 24, 2007 9:58 AM in response to Long Lane

Very hard to say without knowing your domain.

If you like, send me an e-mail from the server/address in question to servertest -at- topicdesk.com and I'll check.

Alex

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Answer 2

Long Lane Author

Level 1

105 points

Feb 24, 2007 10:49 AM in response to pterobyte

done.

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Answer 3

Long Lane Author

Level 1

105 points

Feb 24, 2007 11:02 AM in response to Long Lane

Getting this error message:
Feb 24 18:54:24 mail postfix/smtp[16086]: 9C0CB15F8B6: to=<servertest -at-topicdesk.com>, relay=mail.artpixels.net[212.203.106.235], delay=322, status=deferred (host mail.artpixels.net[212.203.106.235] said: 421 sabertooth.artpixels.net Error: timeout exceeded (in reply to end of DATA command))
Eventually, it might get through.

Lane

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Answer 4

pterobyte

Level 6

11,104 points

Feb 24, 2007 11:08 AM in response to Long Lane

Didn't get anything and my mail server didn't reject anything around that timeframe.

The only thing I see is a connection attempt with a subsequent timeout coming from fischer....... Is that you? If not I'll need an IP or domain name to further investigate.

If it is you, this points to a server misconfiguration or a firewall issue.

Alex

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Answer 5

pterobyte

Level 6

11,104 points

Feb 24, 2007 12:05 PM in response to Long Lane

Don't think it will. It times out during comunication with my mail server.

As I said before, this points to a server misconfiguration or a firewall issue.

Are using a Cisco PIX firewall? There used to be some issues with it.

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Answer 6

Long Lane Author

Level 1

105 points

Feb 24, 2007 12:21 PM in response to pterobyte

That's me... I upgraded my BT Connect recently to 8Mbs and am using the BT Voyager 220V Router with Firewall disabled. Otherwise standard Mac OS X Server config.

It could be that there are upstream issues.

Trying again via .mac

Lane

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Answer 7

pterobyte

Level 6

11,104 points

Feb 24, 2007 12:41 PM in response to Long Lane

Could be.

Usually I have seen this behaviour with "crappy" firewalls or bad MTU settings when using PPPOE.

If you are confident it isn't your equipment, talk to your ISP.

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Answer 8

Long Lane Author

Level 1

105 points

Feb 24, 2007 1:28 PM in response to pterobyte

I found the problem: it was the BT Voyager 220V Router. I switched to the backup DLink 524T (which is now the primary).

Sorry for wasting your time. I noticed, that the email went immediately through...

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Answer 9

pterobyte

Level 6

11,104 points

Feb 25, 2007 12:21 AM in response to Long Lane

No problem. You mails got through.

Alex

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