If you have Apple’s Speech Manager installed, Snap Mail can read mail that you have recieved to you. In addition, you can have the mail being composed in the OutBox read out loud before you send it. This allows you to hear how the text will sound to the receiver.
Use Cmd-= (equals sign) to read selected mail in the InBox. You can select multiple pieces of mail and Snap Mail will read them all.
Use Cmd-, (comma) to pause/restart the reading process.