'Junk' button doesn't interact with Exchange-server-side white/blacklist
It gives a false sense of fulfilling the users intention if you allow people to Block Sender from the Ribbon button, but that doesn't sync anywhere. Likewise, marking as Not Junk, and adding the user to the local Contacts, does not sync to allowed senders, so it still ends up getting caught by server-side filters and doesn't hit the inbox. Client-side Rules for whitelisting have the same effect.
Kevin Cole commented
The junk mail has become so bad lately that I'm considering abandoning my favorite email address and finding another provider. The tools provided by Outlook and Microsoft are not making it easy for me to eliminate unnecessary, unrequested email. This feature needs to be added along with overall improvement to help users eliminate the junk!
Wayne C. commented
It just amazes me that Microsoft would have a feature in Outlook 2016 for Mac that doesn't work, nor did it intend to work.
Ken B commented
Microsoft should be embarrassed that this doesn't work with their own email server software.