I sent an email using Yahoo Mail. Their servers are rather slow from time to time and my browser just stood still. Nothing seemed to happen (I did not get the confirmation). So I decided to log out and log back in and try again, because I thought that it did not send. However, when I checked it, the mail was in the "sent folder", so I did not send it again, since I guessed that it was sent. I am not sure though now.
How is the "sent folder" handled? Is it managed on my account specific? Is it possible for an email to land in the "sent folder" without actually being sent? Basically, is an email first sent and than copied to the "sent folder", or first copied to the "sent folder" and than sent?