Access Exchange server over VPN

Hi all;

I have an end-user with a laptop running Windows Vista and he has Outlook 2007 as his e-mail client software. He is using Checkpoint SecuRemote VPN software to access the corporate Exchange server cluster. Using wireless LAN connection from his home in Australia to access Exchange server cluster in Chicago, USA. Problem: the end-user can connect to the Internet and browse the web....he can also logon to our corporate network using the VPN client. What he can't do is access the Exchange server....the user can "ping" the server and get a proper response...so the datagrams are being routed correctly. I tested his user account on the Exchange server by accessing his e-mail account from my home laptop over my wireless connection in Chicago....so his account is also good.....the user can also access his e-mail over the Internet from Australia using Outlook Web Access with no problem. Question: what can be blocking his SMTP access to his account using Outlook 2007?...I've verified with him over the phone the Outlook configuration is correct....using the IP address of the server rather than the server name so we're not dependent on DNS name resolution. Any suggestions would be greatly appreciated.

Right off hand, it sounds like a permissions issue with the VPN.
Also, if you are NOT the in the IT dept, I'd get them involved. (save you some nasty issues with the company - been there, on the IT side)