Gmail undo send
Have you ever sent an e-mail and immediately thought that you should have aborted that sending? Google has thought the same and has included this feature in Gmail as a part of the Google Labs options: the undo send feature.
If you enable the undo send labs option, you will have 5 seconds to click the undo send button. Most sending mistakes are discovered immediately after sending an e-mail, so 5 seconds would be enough. No more wrong recipients, and mispelled words!
Don't forget your e-mail attachments
My most common mistake is to send an e-mail with a missing attachment, which is followed by an embarrasing "Subject: the attachment" email.
Combine the previous feature with the useful Gmail Labs forgotten attachment detector and forget about this common mistake.
Send only emails when your mind is enough focused
There's also another feature to avoid sending something you later regret: Mail Goggles tests your mind with some simple math problems - if you are too tired working overnight to solve such problems, you better have some rest and retry sending that later.
With all these Gmail features, I hope all our e-mails become error free from now on!