''hunter70 [[#question-1207651|said]]'' <blockquote> I sent a letter to the address info@lasgrav.ru, but received a report on the undelivered mail at fb.com@i.ua - http://prntscr.com/im627u. I searched in my settings where I can hide sending to another box and did not find it. Can you help where it's sitting? </blockquote> Do you have a copy of the original message in your Sent folder? You could right-click this and select Edit As New Message. The error message says "mailbox over quota" which means that the Inbox of the account you sent it to is full.