Question : User's Outlook can't connect to Microsoft Exchange?

A user on my network can't connect to microsoft exchange on outlook through SonicWall SSL VPN but he can connect through non SSL-VPN.
He uses windows Vista and office 2007. We have Windows server 2003.

Earlier today, in  addition to the problem stated above, he also couldn't access mapped drives through SSL VPN but was able to do so through sonicwall SSL-VPN please see http://www.experts-exchange.com/Networking/Windows_Networking/Q_24067875.html .

Answer : User's Outlook can't connect to Microsoft Exchange?

do you have an entry for the servername in your host files? can you ping the server/resolve via dns over vpn?