If you have switched to the "New Outlook" toggle switch in the top right corner:
Unblocking in Outlook takes less than 60 seconds once you know the menu. Now you can restore that connection without digging through support forums. how to unblock contact in outlook
If the person’s emails still go to Junk after unblocking, check your Safe Senders list and add them there. If you have switched to the "New Outlook"
To be safe: