Remark as unread = yes. Kind people have explained how up above. 👍
Recover after deletion = No, I don't believe so..
Remember it = I have no idea. If you can remember what was written in a message you've never seen then that's pretty cool. Haha.
It all just depends on what "call back" or "recall" means in this situation.
EDIT: If you're asking if you can cancel a message you've sent that hasn't been read yet, like taking it back so it wasnt sent, then I don't think so either..