Apple Mail suddenly moving legitimate emails to junk folder
on my iMac running 10.9.5, Apple Mail Version 7.3 (1878.6), and my macbook running OS X 10.10.4, since the weekend many legitimate emails are being sent to the junk folder. So I changed preferences so junk should stay in the inbox, and it's still going to the junk folder. It's set so previous recipients etc are not junk, but people who email me many times a day are suddenly being diagnosed as junk and sent to the junk folder.
Any thoughts?
iMac, OS X Mavericks (10.9.5), 2014 imac