Now here’s something I’m looking forward to playing with: a Windows-based IP PBX! 3CX offers two versions: the free version and an enterprise version. It looks like the primary differences between the versions are that the enterprise edition has product support and will have Exchange integration, although they don’t specify how it will integrate with Exchange. I’ve got a query in to the PR folks who sent me the release, and I’ll post the answer I get.
Update: the answer is that, in this context, “Exchange integration” means that the PBX will send you an e-mail with a voice mail attachment. They don’t yet support Exchange 2007 as a SIP peer. Although their web site doesn’t say it, my understanding is that they don’t yet support SIP over TCP, so they’ll have to get that working first. However, when the next beta ships, it will support the voice-mail-over-SMTP feature with any system. As always, the devil is in the details.