First you have to record audio from your computer. It is very easy and by keeping in mind few professional tips this can be done very well. Read tips from this research paper to do this professionally:

www.technologystation.net/2012/02/computer-sound-recording-free-tools-n.html

After recording audio you just have to upload this audio to your email and send it.

Audio recording from computer is very easy and by keeping in mind few professional tips this can be done very well. Read tips from this research paper to do this professionally:

www.technologystation.net/2012/02/computer-sound-recording-free-tools-n.html

As described in this article there's an audio program called Audacity. It's simple and has a variety of special effects such as amplifying, changing the speed/tempo/pitch, fading in/out and more.