Has it happened to you that you are sending an e-mail with an attachment that is a bit large, and you want to cancel sending the e-mail? I just had this problem and didn’t find a way to cancel the sending which was taking ages since I was sending an e-mail with a video. So what I did was turn the phone on airplane mode and then opened up mail and saw it had problems sending with an explanation mark that I pressed and then I could press edit and choose that e-mail and press delete. Hope this helps if you ever happen to have this problem, especially if you are low on batter at that time 🙂