What I suggested was that you have the faxes go to an Exchange mailbox and then have that mailbox automatically forward the emails to the GMail account.
If you don't have Exchange running, it won't work at all because it needs an SMTP service to use for sending;though, you might be able to add just the SMTP service and get it ot work.
Barring that, you'll have to use a third party solution like FaxTalk: http://www.faxtalk.com/index.htm