Official Gmail Blog: New in Labs: Undo Send - http://gmailblog.blogspot.com/2009...
Undo send. We're going to add some longer time options. - Keith Coleman
haha i just did that mistake. accidentally send an email. ah i wish i had that feature 1 hour ago! - Eren Emre Kanal
That's a BIG Feature! - directeur
Sanjeev will finally be happy! - Bay Chang
Yes I am! - Private Sanjeev
I could have used this a few times when I was working at the G!;-) - John Piscitello
this is awesome ... at this point everyone should be using gmail! - Jay
@Paul Thanks for your original blog post on undo -- It came at a time I was trying to convince some that a 5 second delay would bring way more value than it would harm. It was nice to be able to say, "Well, Paul thinks so." - Michael Leggett
i just used this for the first time a little bit ago. it was awesome! - Dustin
It's very cool. I just used undo on a message I sent in 2002 and now I have my old job back. Thanks gmail! :-) - Kelly Norton
@Kelly Undo Send only let's you undo for 5-10 sec after you send the message. What you want is our Custom Time feature - http://mail.google.com/mail... :) - Michael Leggett
@Michael :) - minus-one
You could always use http://www.deferredsender.com if you want a time window of more than 5-10s - Deepak Jois
I've been waiting for this for a long time. - Benjamin Golub
@Michael Leggett Unfortunately, that won't work either. It will only undo as far back as April 1, 2004! - Anne Bouey
For use this function, I changed my Gmail from Japanese to English version. - @Renchin@