I normally run the connectcomputer script that small business server provides to preconfigure a user in the network. This takes care of configuring the Fax account on Outlook.
For the life of me I can't figure out how to configure it directly on Oulook 2007. I tried sharing the "Mailbox - Fax" and giving the user permissions, like you would to share any other exchange mailbox, but that doesn't work.
Basically, I need to add the "Mailbox - Fax" on a user with Outlook 2007, for all the incoming faxes.