Your question isn't horribly specific, but I'll take a stab at it:
Viewing Web pages shouldn't be a problem. It's a simple HTTP transaction. So long as the Linux machine can connect to port 80 (or whatever port the Web server runs on) on the Windows machine, and vice versa, you're fine.
As for e-mail, Exchange uses a lot of proprietary Microsoft glop that any *nix mail server is probably not going to be able to interact with (e.g. calendering and the like). In terms of just sendinh/receiving mail, however, it's all just SMTP. In fact, I've heard of companies that route all incoming mail through a Linux server running Sendmail or another *nix mail server package which passes the mail through ClamAV and then sends it on to the Exchange server if it's clean.