Citat:
Oops, hit "Send" too soon? Give yourself a grace period of a few seconds to cancel sending, then edit your message before sending again.

http://mail.google.com/mail/help/about_whatsnew.html
Da bi ste aktivirali ovu novinu, u Gmail-u iz Labs tab-a pronadjite 'Undo Send' feature i kliknite na 'enable'.
Citat:
This feature can't pull back an email that's already gone; it just holds your message for five seconds so you have a chance to hit the panic button.
New in Labs: Undo Send