Agree with Bert. I initially set up emails for incoming faxes, but it was much simpler to have it come in a folder. Brooktrout and Mainpine are some of the best modems that integrate with Windows Server.
Maybe Bert can give you some of the benefits of the Brooktrout. For the mainpine, they have US based technical support, 5 year warranty, and drivers that integrate with Windows Server. That allows you to install a fax server/printer on all client computers. To send a fax, all you have to is print said document to the fax printer and wizard will pop up. Also, faxes directly to PDF, email, or TIF. Uses Windows Fax And Scan.