
First lets start with this! What is a MP3 file:
MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, and algorithm, designed to reduce greatly the number of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners.
When you record a song in Jamstudio it will be recorded in a WAVE file.When you upload the file to your e-mail address its changed to a MP3 file.So now it seams you are losing sound Quality.I have listened to your Jamstudio file a few times and I have found that a lot of your instruments are being played in full volume and I hear a lot of Distortion.try going back and edit your sound and then resend the MP3 file to your e-mail address.Remember that if you play an instrument to loud you do not have music,its noise.