In El Capitan on my PowerBook and other of my Macs with more up-to-date operating systems, and iOS13 on my iPhone XR, there seems to be new behavior where some incoming messages have *****SPAM**** in the subject line. In general they are in fact junk mail.
A) I can't figure out how to send those message to the junk mail folder instead of my inbox.
B) And I can't figure out how to mark certain of the messages as not junk. I looked in the customize menu for MacMail on my Powerbook and could not locate a button for Not Junk.
I don't know whether this is a new behavior so that may be beside the point. In any case, any help that can be offered is appreciated.