Your message won't be delivered to the following recipients because moderators can't be reached.

Setup: Windows SBS 2010 with Exchange Server 2010.

While sending an email to another user using owa or from an external emal account, the email does not get delivered.  If sending from owa, a return email is delivered saying "Your message won't be delivered to the following recipients because moderators can't be reached."

I have looked at the message tracking logs and exchange has created a seperate log file MSGTRKMA20130220-1.LOG.  In the log file, the event-id is MODERATORSALLNDR which I cannot find as a valid event-id.

Can anyone help with this?

Thanks in advance.

Brian