Too many good emails go into junk mail

See the articles Reduce junk mail in Mail on Mac - Apple Support

Change Junk Mail preferences in Mail on Mac - Apple Support

The recipients are not necessary using Mac , they might be using windows , the settings to be changed is from their end .

The Mac mail application is corrupted , remove the account and once again add , the fresh settings will be set

Remove email accounts in Mail on Mac - Apple Support

Add an email account to Mail on your Mac - Apple Support

Thanks for sending this but sorry it is not related to my problem.

I can RECEIVE emails ok, but when I SEND from iCloud all recipients say my mails go to their JUNK folder.

I have tested it to my wife's account, always happens when sent from my Mac to her Mac or iPhone.

BUT, if I send from my iPhone or iPad they are received as normal.