I cannot send or receive emails from particular accounts configured in Ms Outlook behind ISA 2006. Ever since I installed ISA, I can only receive/send emails from one particular account, " ...cannot contact the mail server..." that is what is shown in the error message.
I have checked the configurations, I have connected via a different network which does not reside behind ISA and it works fine, so I have dissipated any doubts on whether the mail server was having any sort of problems. The firewall rules seem to be well applied too, I say this because I still can receive/send emails from one of the pop accounts which happens to have the same domain name as the mail server(it is hosted externally).
Any help would be greatly apreciated.