mp3 playback problems

I sent an mp3 to a person in US (by email), which she couldnt play on her mac (cutout after approx 1 minute).
mp3 was created by adaudacity (lame plug-in, I guess) with 144 kbit/s. I have never myself had any problems
playing audacity-origin mp3-files, or heard any of my friends having problems with it.

I offered to send the wav-file, which she turned down in fear of risk of virus content (which I never heard of in that context).
I’m aware that I havent supplied much tech detail here, but any pointers to what might be the problem here?

What options did you select for your mp3 export? Which mode, bitrate, etc.? What version of audacity are you using? What OS? Can you play the mp3 in your computer? In which player? What player is she using? iTunes?

Some players can be picky about some mp3 files, specially if using variable bitrate…