How to tell Mac Mail that a sender isn't spam? I have a business colleauge that my mail prgramme thinks is sending junk mail.
I have added them to my contacts.
I also set up a rule that any email from that address go into my inbox, but neither of those steps have worked and all messages still go into junk.

Can anyone recommend what else I could do?
Many thanks
Lets assume your email provider is gmail.

If that person is marked as Junk Mail in gmail, it will be forwarded as such to your Apple Mail.

To fix it go to your gmail (web site) and fix it there.