We have some remote employees that are unable to access exchange after a migration to Exchange 2010 from 03.
Both users can receive mail with no problem.
MacMail user can send to internal domain email addys but not to external domains. gmail, etc.
Thunderbird user cannot send at all.
I've allowed their IP's on the connector for relay and changed the authentication to accept but it's still not working. what else should i be looking for with Exchange 2010?