No spam folder on some email accounts

[AC Question]

I have 4 email addresses in the email app on android 5.0 on a samsung s5. Two of them have spam folders and the ability to mark emails as spam and any further emails received from that domain goes to the spam folder. That's great. But, two of the email accounts do not have a spam folder, and I can find no way to add one to them. Furthermore there is no way to mark emails on these two accounts as spam, the option simply is not there. All 4 accounts are POP accounts and there is no difference in the way they are set up.

What gives? Does anyone have a clue? I'd sure appreciate it if someone could shed some light on this!

Thank you,
Joe