Question : Problem: Exchange won't connect over Sonicwall VPN

I cannot connect to Microsoft Exchange over my VPN connection with my desktop. The Sonicwall VPN shows as connected but whenever I try to connect to exchange, I am repeatedly asked for my credentials with no forthcoming connection.  However, when I try the same thing with my laptop, connected the same way, I can connect to exchange no problem.  What setting or configuration option on my desktop would prevent an exchange connection?

Answer : Problem: Exchange won't connect over Sonicwall VPN

The issue is that his exchange mailbox is relatively large (6gb) and due to the size of his OST file and other data files (total; 14gb) even with a nicely spec'd laptop everything is choked to a crawl. This is still an ongoing issue but is rather outside the scope of the question; there is no actual problem other than performance it seems.