This will will make it easier to send multiple emails - but doesn't help with large files...
If you open a terminal window and change to the directory where your .mp3 files are, you can do something like this:
Code:
for i in *; do echo "Sending $i" | mailx -s "Session file" -a $i friend@somewhere.com; done
Your version of mail or mailx needs to support attachments though.