I'm sorry, but I'm still confused. Let me ask some specific questions to see if I can understand.
1. When you say you have "set up an exchange email" what do you mean, exactly? Are you running an Exchange server, or are you just connecting to an exchange server somewhere else?
2. Is the incoming mail on all four addresses going to Junk, or is it just on one?
3. What does, "all of my incoming mail on the exchange email is going to my junk folder" mean? Is it on the Exchange server junk mail, or on your iMac and MBP using Mail in the Junk folder? Or is it both?
4. What iMac, what MBP? You can click on the in the upper left corner, then About This Mac and get the details on your systems.
5. In your first post you said
All rules pertaining to this issue in preferences have been done but I'm still having this issue.
Can you tell me what rules pertain to this issue? Junk is normally determined by the system, not from rules?
I think with those answered we can start figuring out what is going on.