For what its worth for those folks using MS Outlook especially on a Mac, you can highlight the email and then choose to 'block the sender' as well as marking it as junk mail. What happens then is that subsequent emails from the blocked person then go straight into the trash ready for deleting.

This option has made a significant contribution to minimising junk and scam emails when I check my mail. I hope the info helps someone else as well.

Cheers,

Andrez