Apple/Mac Mail: How to un-junk a wanted sender
Since Mail does not have an un-junk feature, the best ways to stop welcome senders from ending up persistently in the All Junk folder, are these:
Add the eMail address as new contact in your Contacts app. And set Mail > Settings > Junk Mail. Set The following types of messages are exempt from junk mail filtering to:
✅ Sender of messages is in my Contacts
Or just send the sender an eMail, and mark
✅ Sender of message is in my Previous Recipients.
MacBook Pro 13″, macOS 10.13