How to unsend an email in Gmail

We’ve had the ability to “unsend”
emails in Gmail for about six
years now, but the feature was
somewhat hidden in the obscure
Labs section of Gmail’s settings.
Google officially announced on
Tuesday that “undo send” is an
option in its Gmail service, and
it’s much easier to find in Gmail’s
settings.
Before digging around the
settings to enable undo send, you
need to reload Gmail, otherwise
you won’t find the feature.
Then click the gear icon on the
top left of your inbox, and click
Settings in the menu that pops
up.
You’ll be taken to the general
settings in the “General” tab.
Look/scroll down to find the undo
send feature, and click the box to
enable it.
It’s set to let you unsend an email
for 10 seconds by default, but you
can lengthen and shorten the
send cancellation period from 5,
10, 20, or 30 seconds.
Next time you send an email,
you’ll notice a subtle new “undo”
option in the yellow box that
appears at the top of the Gmail
window after you send an email.
If you realized you missed
something or notice a typo in
your email, click the “undo” link,
and your email will reopen in the
“compose email” box for you to
edit.
Unfortunately, there’s no such
option in the iOS or Android
Gmail mobile apps where small
mobile device keyboards means
our emails are more prone to
mistakes.