Microsoft tends to have a habit of sending cease and desist orders to anyone who makes a program that can do more than read any of their formats, so you won't find many out there that don't cost a pretty penny.
That being said, WMA is about the worst audio format I've ever heard. It can't handle the highs or the lows worth a crap. You'd be better off using a different program to re-rip all the files into MP3 (Ogg Voris is the best of the lossy codecs out there, too bad it suffers from lack of use). If you're going to use MP3 as the format of choice, it's hard to beat the LAME encoder in terms of audio quality in the resulting file. There are some freeware programs out there that use LAME as the encoding engine. Find one, use it, and don't send files like that via email. It just clogs up servers unnecessarily. Upload them to a free web server or something and let people download them from there.
The latest XP update without anyones knowledge, we can not send any music that was ripped via WMP. It is blocked. I have tried 2 audio converters downloaded and both have problems. I need to convert from .wma to wav or MP3. I do graphics and send them via outlook express and include music. I can send my wav or mp3 only but most of mine is wma. Help