outllook97 problems

We have win95/98 computers with both tcp/ip an ipx with Outlook97 clients accessing email from Exchange 5.5. After installing RAS the IPX clients cant access email thru Outlook97. The message says the name cannot be resolved. But (and a big BUT) I can log onto the network with my username and get email. (on the same computer as the other user that cant get email). How come I can get name resolution with my username and the other user cannot? We are logging into a Novel 3.12 server. The Exchange 5.5 server is running WinNT and NWLink.