The things you see in DB Programming are a throwback to when Mitel/Inter-Tel offered an optional seperate external voice mail that replaced the built-in one. That product is no longer available, so to get fax mail on a new install you'd need to upgrade to the MiCollab (MAS) Unified Messaging platform.
However, typically a less expensive solution if you don't need all the MiCollab features is to use a fax server such as MultiTech FaxMinder. Connect it to a couple of SL ports (analog station ports. If you turn on the optional Analog Voice Mail feature you can tell the 5000 it's an extra voice mail and build a phantom ext for each fax user...system will then send call to fax server and then send ext-specific DTMF to get it into the right e-mail address.
