We recently migrated from Exchange 2000 to 2007. We have distribution groups set up that should be able to receive email messages from the outside, but they are no longer functioning after the migration. Using the Mail Flow Troubleshooter I see this result:
“Error submitting mail – Mail submission failed: Error Message: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated.”
Also in message tracking: “550 5.7.1 Resolver.RST.NotAuthorized; not authorized”
Most of the posts that I have seen tell you to check ‘Anonymous Users’ in the Hub Transport Receive Connectors, which is already done. We are not having any other issues sending/receiving messages.
Any ideas…?