Hi.
That's a bit strange, but not impossible, that the person receiving the email does not have a media player capable of understanding G.711 or G.729.
Anyway, I am not aware of any good (stable) mp3 encoder in Java, which could be "plugged into" a UCCX script. And even if there was one, the mp3 format is patented and you would have to buy the license from the Fraunhofer Institute.
I would first save the file in a database or on a remote file system, and use a scheduled process to convert it to mp3 or any different format and then mail it. Not an elegant solution, but it should work.
G.