[BlueOnyx:12573] Mail server disable problem

[William Thackrey]

Hi gents – 

We have a BlueOnyx server (5108R) which hosts several domains.  This server has also
hosted email service for these domains.  Recently we moved the MTA for one of these
domains (call it domain-C.com) to an outside service.  The "disable email for this
domain" checkbox is checked on the server and all mail server aliases have been removed
in the web GUI.

Email sent from any other server to domain-C.com is properly routed to the new MTA. 
Email sent from a user on one of the other domains hosted by this box (call them
domain-A.com and domain-B.com) are returned to the sender by this server with an unknown
user error.  Mail sent from any of our other servers co-located with this one (and which
use the same DNS as this one) are routed properly.

Ideas anyone?  Where does the server find what domains it is the MTA for?

Thanks!