Postfix - SMTP Push

Hi All, I'm sure this problem will be an easy one for you guys an gals out there. I have a friend who would like to change his email MTA server from a Windows based solution to a Linux with Anti-virus and Antu-Spam.. I said that I think Postfix could do the job for him, but I'm new to Linux so I'm no too sure. His ISP does all the work for him.. They push the email's down via SMTP to his windows PC that runs some sort of SMTP software which in turn forwards the email's to an MS Exchange server. My question is, first of all can Postfix do this or is there another package out there that can do it.. If so could you point me in the right direction.. Thanks in advance for your help. Martin