Question : EHLO with a 500

I have been getting the following error somewhat often at random. Sometimes the message goes through fine and others it bounces back with this message in the event log:

A non-delivery report with a status code of 5.5.0 was generated for recipient rfc822;[email protected]m (Message-ID 7F87929010F0D30@exchange02.corp.plazare.com>).  
Cause:  This message indicates a generic protocol error (SMTP error).  For example, the remote SMTP responds to an issued EHLO with a 500 level error and the sending system will QUIT the connection and report this with NDR indicating the remote SMTP server canÆt handle the protocol.    
Solution:  View the SMTP log or run a netmon trace to see why the remote SMTP server rejects the protocol request.

Answer : EHLO with a 500

Have you actually tried to manually connect to any of those domains.
You will need to an nslookup on the MX records and then telnet to the host listed on port 25.
http://www.amset.info/exchange/smtp-diag.asp

Where exactly did you enter the additional DNS Servers? In the DNS Server applet on the domain controllers or somewhere else?

Simon.

--
If your question has been answered, please remember to accept the answer and close the question.