First of all you haven't told us what version of osTicket you are running, so we cannot tailor our reply to you.I have never seen the system get the wrong sender email. What email software are you running? Whats your use case that if cannot find the sender?Q: But I can't remove the wrong recipient???!A: Sure you can, edit the ticket.Q: neither I can change the email address of the first recipientA: Sure you can, edit the user.Please help us to help you by reading and following the posting guidelines located in this thread: Please read before requesting assistance. The more information you give us the better we will be able to assist you. Thank you.