Help needed to interpret SMTPDiag results

Posted on 2010-08-31
Last Modified: 2012-08-14
I have a MS Exchange 2003 smtp queue of undeliverable mails to a particular email domain (
I did a
smtpdiag /v
with results in attachment.
From what I could make out from the results, there does not seem to be any issue. Yet the queue stubbornly stays unmoved. Meanwhile outbound mails to other recipients continue as usual.

Administrative support of the receiving domain, claim that they do not use any spam filters. In any case, if sender, is blacklisted, would'nt their mail server had rejected the connection?

Could an experts please help interpret the diagnostic results and suggest further trouble-shooting procedures?
Thank you very much for helping with reducing the stress!
Question by:garychu
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LVL 13

Expert Comment

ID: 33566470
Looking over your log, the SMTP sequence of commands is normal and does not show any failure.

Expert Comment

ID: 33566559
If you force the queue to process do you see any errors in the logs?
LVL 30

Expert Comment

by:Rich Weissler
ID: 33566584
Concur with MarkusDamen -- all looks good in that log file.

Bigpond apparently has one MX record that I see, with two hosts for that address -- and when I just attempted to connect on port 25 they (both of them) were VERY slow to respond.  Therefore, I would strongly suspect the slow response of the destination mail servers is your culprit.
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LVL 28

Assisted Solution

sunnyc7 earned 500 total points
ID: 33566615
Your SMTPDiag looks ok - no issues there

Right click on the queue name Click Unfreeze.
LVL 27

Expert Comment

ID: 33566676
Check your IP is not on any blacklists as a matter of course.

Also check it isn't one particular email that is causing a backlog, perhaps a large email?


Author Comment

ID: 33571315
Thanks for the overwhelmingly quick resposnes, experts.

radnbne: Forcing the queue does not change the status. Not sure which log you meant.

Razmus: But the queue has been stuck for nearly a week now. Bigpond is the biggest ISP in Australia. I assume that at some stage, one or other of the mail servers would be free.

sunnyc7: Do you mean first freeze and then unfreeze?

shauncroucher: Yes, the IP is listed on 2 to 3 dnsbl lists. (It's hard to be not listed by at least one or two at any one time. I may be wrong, but I suspect that some are dubious. For instance, UCEPROTECTL1 asks for USD97 to be delisted immediately. Others require such details for the request - suggesting that they in fact make up mailing lists.). In any case, would it have mattered if Bigpond support insists that they do not filter spam. (Hard to believe!). If the IP is listed, would the smtp connection be still successful, yet mail could not be delivered.

I will remove the queue and ask users to re-send. Then see what happens.

Thanks in the meantime.

Author Comment

ID: 33573613
Have since deleted the old stuck queue.
But seem to have made no difference.
Have also tried an smtpdiag analysis from another site. This other site uses the same ISP and DNS servers.
Attached is the result. It looks pretty much the same as the problem one.
I still feel that the most likely cause would be listing on an RBL.
But how do I get to convince the support guys at Bigpond - roos with head in the sand attitude!

Expert Comment

ID: 33573850
A global RBL Check finds no issues with their server.  Your own test managed to send the email without a problem, this would not have happened if RBL was involved.

I think you need proof that bigpond is at fault.  Usually when I send mail to an account on the blacklist the message sis accepted for delivery and then a rejection message comes back.  

Are you getting any bounced messages?

LVL 27

Expert Comment

ID: 33574120
Usually you would get a bounce back. If you are on any blackest, you do need to get that resolved and it is likely to be the cause. You should find out how you ended up on it in the first place too.

LVL 28

Expert Comment

ID: 33575144
Can you try restarting the server once ?

Author Comment

ID: 33581917
I can confirm that the sender domain still remains on a couple of the lists. Unreasonable amount of monies are demanded for immediate delisting - otherwise will take another 1-2 weeks. Who is worse, spammers or people who are supposed to help control spams?
No bounc-backs from which could be their policy of not doing so.
Have also re-started the server.
Biggest mistake was to have allowed the black-listing to have happen. Even changes of IP will not help if the problem of finding the spambot is not first dealt with.
Would you agree that as far as interpreting the smtpdiag log is concerned, the issue is now settled?
LVL 28

Accepted Solution

sunnyc7 earned 500 total points
ID: 33581937
Same issue with SORBS @ see here

They request a donation to get you off the list.

If you need a quickfix
talk to your ISP
Ask them what is the charge for their smarthost service per month - it should be minimal.
Configure your exchange using the smarthost and start relaying.

its a nightmare when you get into such delisting issues. Its not worth the time trying to plead with them to get off.
Get smarthost / start mailing.

Author Closing Comment

ID: 33582895
Thanks, experts.
With your inputs I think I now have enough to proceed further.

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