E-Mail stuck in queue - SMTP Protocol Error Occurred

Hey guys,

My boss is trying to send mail to our insurance company and within two minutes, he gets a notification delay. When looking at System Manager, the message is stuck in the queue with retry status and a message of "An SMTP Error Occurred"

We're not an open relay and we've been able to send mail to the domain before...the IT manager for the insurance company says there's nothing wrong with their server, and I'm wracking my brain...don't know what to do. I thought maybe restarting SMTPSVC would work and nothing happens. Any thoughts?
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Go to the Microsoft site and download SMTP Diag. Use this tool after installing it on the exchange server to test the user/recipient email sending process. You may get an insight as to the cause.


There is also a small application to  learn about the Error Code that is given.

Use the above to ID the cause of the error.

So far the question you have posted is very generic and there could be many reasons for the problem. The reason that I have mentioned the two tools above is to (hopefully) figure out whether it is an SMTP related issue.

There is another method you can use. That is to Telnet the receiving server from your email server using the actual email accounts that are used. See if the server accpets the email from your sender. You should know Telnet and NSLOOKUP commands for this. If you dont, please use Google to do a little research.

Just to be safe, go to www.dnsstuff.com and check your domain using the DNS Report tool. I loved it when they were free.  That was a long time ago.

Let us know what your investigations turn up.


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pitsbrosAuthor Commented:
That worked great! I was able to find that Barracuda Software has us on a poor reputation list and that was causing us to be blocked from the recipients server. Thank you so much!

Great tool!
A pleasure to have helped you.
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