TechTips: Don't Recall, Delay (Your Email, That Is)
Instead of saying 'oops' and sending out a recall request after re-reading the email and realizing I completely mis-read the intent (or other reasons behind office seppuku), I've told Outlook to queue my mail for a few minutes before sending.
In Outlook 2007, Tools -> Options -> Mail Setup
Uncheck 'Send immediately when connected.
Send/Receive -> Schedule an automatic send/receive every [5] minutes.