501 error trying to send external mail
Posted on 2007-11-23
I've spent the last few days migrating off of Exchange 2003 to 2007 and shutting down the 2003 server. But now I'm having problems with sending email outbound.
I have a send connector, * is the name space and I have my smarthost configured (same way that worked with Ex2003) and I have the response setup to my external mail server's name. So, I have mydomain.local internally, but have mydomain.com externally. The external mail server's name is mail.mydomain.com and that's what's in the response page of the send connector - just like I had in 2003.
However, I don't even think emails are getting that far. Everytime I try to send an email externally, it fails nearly immediately and I get this message:
The following organization rejected your message: home.
followed by 'diagnostic information'
home #501 Your domain does not seem to be valid. Could not find MX record for your domain. ##
I have no clue what 'home' is on my network.
Anyway, I am at wit's end on this - any help would be greatly appreciated. This was the same setup that worked fine before.