Restore a Draft of a Message
Restore a Draft of Your Email Message
While composing an email, a draft of the body of the email will be saved locally so that, if you get logged out or something happens, when you go back, you can recall the draft of your email. It can be accessed by going to File >> Restore Last Draft in the Text Editor where you compose the body of your email.
One draft is saved per email editor / interface / user.