If email from a blocked sender still appears in your inbox, that sender might be using spoofing to hide their real email address. Try the following solutions.
Note: Blocking a sender doesn't prevent email from going to your Junk Email folder. By design, messages from blocked senders are automatically moved to your Junk Email folder.
Check if a sender is spoofing their email address
Some senders use spoofing to disguise their email address. Check if the email address is different than it appears, and add it to your blocked senders list. Visit View internet message headers in Outlook to learn more.
Create an inbox rule
Use a Microsoft app
If junk email processing isn't working correctly and you're using a third-party mail app, try using a Microsoft app such as Mail for Windows 10 or Outlook for Windows.