Type type type type, send. AUGH! WAIT! NO!
We've all had it happen. You click Send, type Alt-S or press Ctrl-Enter to send your message off, and 1.3 milliseconds later you realize that you sent it to the wrong person, had a typo, or forgot the attachment. Usually this only happens once every couple months but it happened twice to me today. Thankfully neither will get me fired, but it's still embarrassing and potentially threatening to your stream of income.
Talk radio has a 7-second delay so they can hit the "dump button." Email should have the same thing. It turns out to be very easy and the feature is built into Outlook. The explanation comes from http://computersoftware.suite101.com/article.cfm/delay_sending_email.