Dear OverFifty
Thank you for posting to Microsoft Community
For a large number of spam emails from different senders, it's troublesome to block the sender alone. I understand that these emails are already in your spam mailbox, so you can choose to delete suspicious spam emails permanently.
Steps: Open Junk Mailbox, right-click on any junk mail 》 Junk Mail 》 Junk Mail Options 》permanently delete suspicious junk mails instead of moving them to Junk Mail folder.

I hope this information is helpful and if you have any questions, please let me know and I'll be happy to help.
I wish you all the best
Linda.W-MSFT | Microsoft Community Support Specialist
I too have this same problem. Please get something where we can block (block, not send to junk, completely block the email from being received) from all email addresses that are preview@ and have a wildcard for the domain.
I have the rule set, so the emails always go to junk, but I DON'T WANT THEM AT ALL. Just allow me to block all emails from preview@.
Also, I have changed my setting to permanently delete junk mail instead of delivering it, and it doesn't work, it still delivers it.
Its so annoying and the sender should be fined for harassing people. In the last five minutes i was typing this email i received two more junk mails, see below. always from preview@
From Subject Received Size Categories
Factor | Affiliate We provide fresh, ready-made meals that support even the busiest of lifestyles! 11:13 PM 32 KB
Factor | Affiliate <*******@sceyer.com
Factor Affiliate No commitments, except to yourself. You can pause, cancel or change your plan at any time. 11:08 PM 32 KB
Factor Affiliate ******@defreliant.com