Whether you send it to a MAC or a PC, the receiver must have a media player that will accept the file extension.

The Quicktime program should be able to play .avi files, at least the one on this PC does. I haven't checked the most recent MAC version of Quicktime though. The receiver may need to adjust their "File Type" settings in the "Preferences" section.

For .avi or .wmv, they could also install the Windows Media Player on their MAC. Here's a link:

http://www.microsoft.com/windows/windowsmedia/software/Macintosh/osx/default.aspx

Hope this helps.

Grif