in my out going mail all options are grayed out.

My out going mail has been hijacked. I found a local mailbox with mailbox called x-iphone-sender and others. It is set up so I only have these choices: mark, move or archive. All of theae lead to that local mailbox hacker created in my Icloud. All mail is hijacked to this mailbox. when all is sent to move, the page only opens for 1 sec. then shut very fast not allowinng me to see this mailbox