If it makes you feel better, however, I am in contact with the IOS folks trying to get them to make a few changes that will make this possible for inbound faxes at least. Currently there's some painful limitations with what you can do with a fax on the router (i.e. it can't switch between a voice channel to fax... it has to know it's a fax that hits the port, getting the DID information into the body/subject of the resulting email isn't flying, it assumes it needs to be stuffed into the SMTP address itself etc...).
If they can help us out, we'll pursue all IP fax routing for at least the inbound portion. Can't say if/when that will happen but be aware it is on my radar at all times. Outbound is a little trickier nut to crack, unfortunately, so that would probably have to roll in later.
Jeff Lindborg
Unity Product Architect/Answer Monkey
Cisco Systems
lindborg@cisco.com
http://www.AnswerMonkey.net (new page for Unity support tools and scripts)
