how to send MP3 files?

Well, yes, there is a way to send a file that is too big to fit in one attachment. The basic process is to uuencode the file, split the the result into a number of smaller pieces, and email each of the pieces separately. At the other end the parts are re-assembled in order and run though uudecode to recover the original file. On a Unix or Linux system you can use shar/unshar from the Gnu sharutils package (ftp://ftp.gnu.org/gnu/sharutils/) to easily accomplish the uuencode and splitting and well as the re-assembly and uudecoding of the parts at the other end.

Yeah of course as far as this windows environment is considered you can use a utility called as asplit and ajoin can be used which is readily available in internet.  What you have to do is just split the MP3 file in to smaller size by using asplit and send each file to the receipent and send this ajoin utility there they can join the file.  

If the person you are sending the files to has a limit of say 3 megs, splitting files larger than 2.5 megs and sending them all at once will probably fail.

Ask the recepient how much space they have, then split your files to about 2/3's that size.  (because binary files need to be encoded, they get larger)  Send one piece, ask for a email reply, then send the next piece till you are done.

big pain in the neck.

You might consider a free space site on the internet to hold your files, then just email pointers to your friends to download at thier leisure.  One such service is http://www.freedrive.com/GetMain.asp?menuid=whysignup

You could also use personal web space from your ISP account and ftp files there or sign up for any of the may free web sites.  I think http://geocities.yahoo.com/home/ offers such.

do one thing
1. convert the mp3 into wav format
2. resample the wav file digitally with less sampling freq and mono channel
3. convert into mp3 with lower bitrate and frequency matching with new wav file..

now you'll get a much smaller file (sometimes less than 1mb) which can be sent via mail also...
sound quality reduces but not so much that you cannot listen to song...