|T O P I C R E V I E W
||Posted - 04/26/2012 : 11:22:08 AM
Hello, I have a client running SBS 2003/Exchange 2003. Mail to 3 different domains keeps getting stuck in the SMTP Connector queue. If I restart the server, they will ususally flush out and deliver as expected, but what I can't figure out is why they are getting stuck in the first place. I am able to resolve the domain using NSLookup and resolve the mail server by setting the type to MX so it doesn't seem to be a DNS issue.
I ran an external mail server test (MX Toolbox) and it showed that TLS was not available, but I am not sure if this would cause the mail to get stuck. I thought perhaps a specific email might be 'plugging' up the queue, so I deleted the oldest emails for all 3 domains, but that didn't help.
Any ideas on where else to look?
|4 L A T E S T R E P L I E S (Newest First)
||Posted - 06/02/2012 : 10:00:56 AM
Is it possible you are simply being blocked upstream? I have seen this behavior when the IP of your server is on a blacklist.
||Posted - 04/26/2012 : 7:24:25 PM
Thanks for your response. Sorry about the other post- I wasn't sure whether to post under SBS or Exchange. At any rate, no issues with the SMTP utility, all tests passed. SMTP timed out when trying to stop it via the services page, but I killed it using taskkill. After restarting, I ran the SMTP diagnostic several times. Went back to the queues and 'presto' mail was gone and all queues are empty. I assume that restarting SMTP emptied the queues; still not sure why they keep sticking though. Thanks for your help Joe.
||Posted - 04/26/2012 : 4:29:54 PM
Will you delete the other one - you would not believe how many minor heart attacks you gave me
||Posted - 04/26/2012 : 4:28:55 PM
What is in the event logs?
What happens if you just restart the SMTP service?
What happens if you run SMTP Diag? - http://www.microsoft.com/en-us/download/details.aspx?id=11393
By default the command NSlookup uses the first DNS server assigned on the network card and not the DNS server that the SMTP service may be trying to use.
Try to telnet to the smtp recipient server of the stuck mail and send a test email - http://thedaneshproject.com/posts/send-mail-through-smtp-using-telnet/