Is it possible to compress an mp3 file?

Hello,

An mp3 file is already compressed. So the gain from using a compression software is nearly negligible. Also, lowering the bitrate of an mp3 will result in a loss of sound quality.
The best option is to use a file transfer service like wetransfer for example https://wetransfer.com
You upload your file and then provide the email address of the person you wish to send it to. Your recipient will receive an email with a download link and can then retrieve the file.

Best regards.

Hello,

There are many temporary storage sites such as:
DLFree: http://dl.free.fr/index_nojs.pl
Partage-Fichiers: https://www.partage-fichiers.com/
Sendspace: https://www.sendspace.com/
FileDropper: https://www.filedropper.com/
Others....

Try another one by including the provided URL link in an email you send to your correspondent so they can retrieve the file themselves.

Best regards
--
Long live Bobo! ~ Little fish will grow big ~

You can compress it by lowering the bitrate, but this reduces the quality of the file:
https://www.mp3smaller.com/fr/