AOL and sit in outbound que then "SMTP Protocol Error"

Any email messages sent from inside the company to and sit in the outbound que of the Exchange server and aren't sent. Then an "SMTP Protocol Error" is received (that is the only message). Then an "NDR Report is sent back to the sender.

How do I go about resolving this problem?
Who is Participating?
Could be either a DNS issue or AOL just don't like you.

Can you do an nslookup on AOL's MX records from the server?
If you go to and put in your domain, does it flag any errors?

If you are on a dynamic IP address or certain types of DSL connection, then AOL will not accept your connection.
You will probably have to use an SMTP Connector to route the email via your ISP:

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.