I just took a look at their site and the application that is offered for download is for Windows machines only.
The file extension is .exe which is not an extension that runs in OS X.
However, if you have Parallels or VM Fusion installed, you could run XP or Vista on your Mac and then run the Incredimail program.
I downloaded 'Incredimail' but it does not open. The pop-up window says "the movie could not be opened"!!! What does that mean? I'm pretty new to the 'mac world' and have no idea what this means. Could anyone help me figure this out?