Gmail does have a lab, called Undo Send, which allows you to press Undo after you have sent an email.
Labs are a "testing ground for experimental Gmail features that aren't quite ready for primetime." Many of the popular labs end up becoming a full feature of Gmail. Undo Send is one of the popular labs that I am sure will be making it's way to primetime soon.
To set up Undo Send in your Gmail, follow the steps below.
- Go to Settings.
- Click on the “Labs” Tab.
- Search for Undo Send (or scroll down until you see it).
- Choose “Enable” to add the Undo Send lab.
- Don’t forget to press “Save Changes” at the bottom of the page.
- After pressing save, you will automatically be taken back to your inbox.
- Click on Settings again. You will be on the “General” Tab in your Settings.
- Scroll down to “Undo Send:”
- Change the cancellation period to 30 secs.
- Press "Save Changes" at the bottom of your page.
- Now, when you compose an email and then press send, you will get a yellow popup at the top of your inbox. You have 30 seconds to press undo. The email draft will show back up, and you can edit it, add an attachment, or delete the draft.
- The way that this works is that the lab delays sending your email for 30 seconds. So no one will actually get the email if you press undo. This is very different then how the retract email worked in Groupwise.
There are a lot of other great labs and some apps that you can use to simplify things when you use Gmail. Here's some more info about other Gmail Labs and Apps.