How do I prevent emails from contacts being cla...

Certain emails are classified as junk even though the person is in my contacts.

They were probably put there by the server. Go to the webmail site of your provider and mark them as not spam there if possible.

It only happens in the Mail app. It does not happen in Outlook nor on the AT&T webmail site.

What color are they, if Brown, Mail did it, if normal, Mail did not do it

So, what color are they?

Brown.

If that is so, then you might need to reset the junk filter. Open Mail preferences, then Junk, and Reset.

Follow Glenns advice.

Did it. Will have to have one of the senders test it to see if the problem is solved.

最后更新：2017-08-23 22:20:45