Another day, another new feature in Gmail Labs. This one
could be more useful than most, as it's something you probably have a
reason to use with some frequency. It's called 'Undo Send,' and as the
name suggests,
it lets you take back a sent email,
as long as you act quickly enough. After enabling the feature, Undo
Send works much like Gmail's other 'undo' features. When you send an
email, you get a message confirming it has been sent, along with a link
to 'Undo.' This message lasts for 5 seconds, at which point you lose
the opportunity to take it back. While that might not be much time,
it's probably enough to pull back emails where you forget an
attachment, forget to cc someone, or catch an obvious typo.