If you want to record your own voice to send, try using Audacity (download at http://audacity.sourceforge.net/) and 'export as mp3' to send.
There's a list of other free download programs here:
...use mp3 for emailing files as it's one of the most compact formats for audio. Don't use 'wav' format, as that's 10 times as large as mp3 (even though wav is higher quality).
There is a program which records from your sound card, meaning whatever you hear on your speakers can be recorded. I'll see if I can find it.