Using classic Outlook for Windows in business environments
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