2003 server DNS issue
OK, this is a problem I have been looking into for a few hours.
I have a 2003 AD domain with 2 domain controllers. One of which is an exchange 2003 server sp2. I had a user tell me he got a delay notice upon sending an email to a sister company of ours that has been done successfully thousands of times. I looked in the queue and saw there were several messages from several different users stuck in the queue all to the same domain, but different users. So as it stood, I could not send an email to anybody in the external domain.
First thought is of course DNS. I am able to resolve every other address to any other domain in the world. This is the ONLY domain who mail is queued for. So I figure that domain must be having problems. Well, no they are not. I am able to telnet to the external exchange server just fine from all of our other sister companies.
I then try to ping the mx record for that domain and get the host could not be resolved. This is mysterious to me since we send a bunch of email to this same company every day and all of a sudden, with absolutely no changes, it stops. I am sending email using DNS from our exchange server. So I say, its a DNS problem. Well, no its not that either. I try to ping the IP of the mx record and get a request timed out. I am able to ping that mx record from any other domain except for the one in question, so I can say with certainty that it is not a DNS issue. The external domain is not limiting a ping reply to certain IP's.
I then tried to do a tracert on the IP of their mx record. It shows that it made it out of my ISP and made it to their ISP but then drops off there. So I can say that it is not a problem on my T1 or my ISP.
Is there any advice from anyone on what else it may be?
Thanks.
I have a 2003 AD domain with 2 domain controllers. One of which is an exchange 2003 server sp2. I had a user tell me he got a delay notice upon sending an email to a sister company of ours that has been done successfully thousands of times. I looked in the queue and saw there were several messages from several different users stuck in the queue all to the same domain, but different users. So as it stood, I could not send an email to anybody in the external domain.
First thought is of course DNS. I am able to resolve every other address to any other domain in the world. This is the ONLY domain who mail is queued for. So I figure that domain must be having problems. Well, no they are not. I am able to telnet to the external exchange server just fine from all of our other sister companies.
I then try to ping the mx record for that domain and get the host could not be resolved. This is mysterious to me since we send a bunch of email to this same company every day and all of a sudden, with absolutely no changes, it stops. I am sending email using DNS from our exchange server. So I say, its a DNS problem. Well, no its not that either. I try to ping the IP of the mx record and get a request timed out. I am able to ping that mx record from any other domain except for the one in question, so I can say with certainty that it is not a DNS issue. The external domain is not limiting a ping reply to certain IP's.
I then tried to do a tracert on the IP of their mx record. It shows that it made it out of my ISP and made it to their ISP but then drops off there. So I can say that it is not a problem on my T1 or my ISP.
Is there any advice from anyone on what else it may be?
Thanks.
ASKER
I tried dnsstuff and we dont show on any blacklists. We have 5 sister companies that I manage and there is only 1 having trouble. Let me bring up again that this is not just email that is being affected. I cannot ping them either by FQDN or IP. A trace route shows that I make it to their ISP and then the connection gets dropped. The other office is not experiencing any problems.
Thanks.
Thanks.
ASKER CERTIFIED SOLUTION
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ASKER
I contacted someone in the remote site and they suggested they were having the same problem sending email to us. So anybody that sends email to us from their site is stuck in their queue and any mail sent from us to them is stuck in the queue.
He stated there was nothing on their firewall that would be causing this, but neither of us has come up with a solution yet or a good explanation as to why its happening.
I am still trying to get their OWA address to try. I gave them ours and will post here if they are able to open ours when they let me know.
The remote site is not having any other network problems. They did say that a few other companies were getting email bounced back to them, but we are not getting any bounebacks, just email stuck in the queue.
Thanks again.
He stated there was nothing on their firewall that would be causing this, but neither of us has come up with a solution yet or a good explanation as to why its happening.
I am still trying to get their OWA address to try. I gave them ours and will post here if they are able to open ours when they let me know.
The remote site is not having any other network problems. They did say that a few other companies were getting email bounced back to them, but we are not getting any bounebacks, just email stuck in the queue.
Thanks again.
ASKER
The remote site blocked all traffic from a range of IP's from my ISP because someone had been linked to a daycare web cam all day long. So they fixed that and all is working again.
Thanks.
Thanks.
The other option could be that they are using a blacklist and your domain got listed on it. I would call them and see if they are having trouble sending/recving email.
You can also look up your domain on dnsstuff.com to see if you have been mistakenly blacklisted anywhere.