VMPro can detect fax tone yes. But only once the call has reached a greeting. As I said, when a lot of people read the documentation and see "fax detection" they think that the system can detect fax tone before it reaches the phone and route faxes to a fax server and voice calls to the phone. This is not the case. If a call ends up at voicemail then it can then detect fax tone.
VMPro can detect fax tone and then like anything in VMPro, can do any action you want it to. You could transfer it to an xtn which has a standard fax machine connected. Or you could send it to a voicemail box and leave a message. I think then, as long as it's in Intuity mode, you can logon to the mailbox just like any other and select where to send the fax (any xtn). You can't email the fax image like this. It's just a voice recording of a fax screeching. To email the image, you need a fax server of some kind.
Fax servers, depending on country and depending on how many licences, can be from US$800-3000ish (that's very rough). Depending on how you want it set up, you could just route calls on different DDIs to different xtns with fax machines. It's depends on what you want to do.