I am running unified messaging in the configuration that you are wishing for. There were a TON of road blocks, but I got through them.
1st: you must uninstall unified messaging, and re-install it, in the non-eschange mode.
2nd: I use AT&T U-Verse for my ISP, so I had to create a mail user with U-Verse and use it as the sender (U-Verse would not allow a non-U Verse sender to send mail over their service). SO, I have every mailbox that is set up for unified messaging use the same e-mail address as the sender.
3rd: U-Verse had port 25 blocked by default (this is the SMTP sendmail port), and port 25 is the ONLY port that the unified messaging software can send on. So I called U-Verse to open port 25 transmission. This took about 1 minute, as the first tech that ansered the phone knew exactly what I was asking for.
Finally, I had to adjust my McAfee virus protection software to ALLOW port 25 transmission (the default is blocked, to prevent mass mailing worms from sending mail).
Of course, your meriln mail and the PC running Unified Messaging must be on the same network, same dafault gateway.
Prior to U-Verse installation, I was using Bellsouth.net DSL; they were not so tight on the originating e-mail address, matching their service.
I've been using Unified messaging in this mode for a very long time, and it is VERY reliable. It will take much trial and error on your part to get it set up, but it is worth the effort. I receive my notifications in my mailbox, and on my Blackberry SECONDS after a message is left on the voicemail. Overall, AT&T's unified messaging is a great, low cost, reliable solution.
I do have some additional notes about the logfile and what the result codes mean, if you need them. I don't have the info here, but if you need it, please reply, and I'll get it out here in the next 24 hours.
