I spent alot of time trying PC based (Windows) software, and settled on this one:
[Link: toscintl.com]Call Soft Pro
Shareware with a registration of $49, which I gladly paid after using it for a week. I am amazed at the level of features that is in this software, so it is actually quite a bargin.
I am using it with a main menu, 3 mailboxes, and it makes mpg's of my messages and emails them to me. It also does faxes, however I have not used that feature.
If you try it, do pay attention to the recommended modem list. The first modem I tried had low voice levels which caused some cut off messages. So I went out to Fry's and got one of the modems on the list (Zoom 3025C), and it works very reliably now.