I recently migrated from 2003 SBS to Exchange 2010. Since that time I have been receiving 5015 & 5016 Application Event errors. Complaining about the Small Business SMTP Connector (Microsoft Exchange cannot find a route to the source transport server or home MTA - And - The Active Directory topology service could not discover any route to connector ). I Went to Exchange Managment Console, Microsoft Exchange, Microsoft Exchange On Premises, Organization Configuration, Hub Transport, Send Connector Tab and see two.
1-Exch2010SMTP (Source Server - ExSrv; Network = RouteMailThrough-my.smarthost.net)
2-SmallBusinessSMTPConnector - SourceServer - 'none listed', Network = DNS/MX)
I tried to disable the SmallBusinessSMTPConnector and recieved an error...
because it requires the object to have version (8.0.535.0). The Object current version is 0.0 (6.5.6500.0).