Ya i have that enabled, but it only works for a few seconds. Also if I click another link after clicking send (which I usually do, I usually go to inbox) I lose the chance to edit it. I think it would be useful to have the ability to edit the email for a few minutes after you send most times I don't realize immediately there is a change I want to make, but I usually do realize it within 2 minutes.
Fair enough! I've just gotten used to seeing the Undo link in gmail...but I've never actually had to use it.
I believe it's a 5 or 10 second delay
for that labs feature. Something more similar to commenting on HN might be interesting. Allowing someone to edit/delete for up to several minutes before the email is officially sent..
You can now increase it up to 20 seconds from the "General" tab in Settings. As of now, the only choices are 5, 10, and 20 seconds.