Windows 2003/exchange 2003 page file size

I have Windows 2003 and Exchange 2003 running on a new dell server. The page file was set for 2000-4000. The mail boxes have not been moved over to the server yet. I received a messaged that virtual memory was low and would be increased. While looking at the performance window the page file keeps increasing in size up to 5gig.

We have been on the phone with Microsoft for 4 hours and they dont seem to know what the problem is.