You may have heard that Exchange 2010 won’t support inbound fax. I have yet to find an Exchange 2007 deployment that actually uses Exchange UM faxing for one simple reason: it’s inbound-only. If you have to do all the work of deploying an outbound fax solution anyway, the value of inbound fax support in Exchange UM is quite a bit lower.
Exchange 2010 won’t create fax messages itself. However, there’s a twist: you can outsource your fax over IP (FoIP) capabilities. Exchange 2010 will honor any existing Exchange 2007 UM fax configuration properties, and it will continue to recognize fax CNG tones. However, instead of answering the call itself, UM will look at a new configuration property defined on UM mailbox policy objects: FaxServerURI. If this property exists, UM will try to hand off the call to the specified fax solution. The external fax solution will establish a fax media session with the sender, create a fax message, and send it to the UM-enabled user’s mailbox.
Messages created by this approach will look basically just like Exchange 2007 UM fax messages, and they’ll appear in the Fax search folder just as existing messages do.
The foregoing discussion might lead you to wonder who’s going to offer FoIP services that work with Exchange 2010. I haven’t seen a list yet. However, Concord Technologies sent out a press release at the Worldwide Partner Conference touting the fact that they’d be offering an Exchange 2010-compatible solution, so I guess we can count them in.