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DNS or not?

Afternoon All,

Exchange Server 5.5, SP4.

One domain will not leave my IMS queue.  Their inbound mail works like a charm, but if I respond to it - just hangs in the queue as [Host unreachable].

I had a stray DNS # (of three) but browsing the Internet was/is working fine, however I removed the stray DNS entry just the same.  NSLOOKUP reports back:

Server:ns1.host.net    (not exactly - names have been changed to protect the innocent)
Address: IP address of my DNS

If I set type=mx and type the domain name that will not leave my queue, I get Name servers, dhcp server and mail server associated with the domain in question.  Does this mean the problem lies in between me and the domain in question?

I cannot telnet to the mail server over port 25 either, but I can from my home via the Internet.

I checked URLSACN logs and everything... cannot find a reason for the madness.... Their end claims it is my end, but this has been an on going thing that I would like to put to rest...  Any assistance would ROCK!

Thanks Guys (and ladies),


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Last Comment
David Wilhoit

8/22/2022 - Mon
David Wilhoit

if you can connect to their SMTP from everywhere but your office location, that's a pretty good indicator that something is blocking your IP or SMTP domain. that would occur on THEIR server,not yours. Unless you specified somewhere to not send to this domain, and I haven't found that trick yet.

If you can telnet to port 25 on 9 different servers, but not on theirs, it's their problem. Prove it to them....

David Wilhoit

alternately, since you had a dead DNS server, ipconfig /flushdns, restart netlogon service.


Thanks D.  That's just it though, how can I prove this to them?  I have enabled all exchange  diagnostics and message tracking etc, but nothing is giving me a specific point of failure as I sort through the seemingly endless amount of logs!

Do you know of a way I can provide this info?

Experts Exchange is like having an extremely knowledgeable team sitting and waiting for your call. Couldn't do my job half as well as I do without it!
James Murphy
David Wilhoit

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