Finally I have written a long email, and just about to send, trying to click Send & resolve button but a little bit wrong and mistakely click the neibour- which is cancel button. And the mail is gone! I have to write it again from the beginning! It's wasting time.

And after I have sent the email, the email is in the sending box, but I want to edit a little bit, but it's only cancel button? so I have to write it again from the beggining.