Google's Gmail service has enabled two new features that prevent you from making common e-mail mistakes: sending a message to the wrong person and forgetting to include someone on the senders list. The features, called "Don't forget Bob" and "Got the wrong Bob?" were in beta testing via Gmail Labs, and are now implemented by default to every Gmail user.
Over the next day or so, Google says that you should start seeing the new features in Gmail, if you haven't had them enabled via Labs already. Once they are enabled, as you type in your recipients, Gmail will make suggestions automatically based on the groups of people you usually e-mail.
Don't forget Bob
The Don't forget Bob feature suggests recipients for your e-mail while you compose the message. The feature suggests people you might want to include based on your most contacted groups of people. The feature kicks in when you enter at least two recipients.
For example, if you regularly e-mail your mother, father, and sister together, then the next time you start composing a message to your parents, Gmail will suggest you add your sister, too. A similar example works for work-related groups. Once you click on a suggested name, that person will get added to your e-mail.
Got the wrong Bob?
The Got the wrong Bob? feature can be a life-saver and spare you some embarrassment. Again, the feature is based on groups of people you e-mail most often, so Gmail will try to figure out if you have accidentally included the wrong person in the recipients list (before it's too late).
For example, if you usually e-mail a group of friends, and one of them has a similar name as your boss (and you typed it in by mistake), Gmail will warn you that you might be making a mistake. This feature, like Don't forget Bob, kicks in when you add more than two people to your recipients list.