Sending, receiving, and organizing email in Outlook.com
I can only say what worked for me. I was getting 50 to 100 emails from them every day, but they were already going into my JUNK folder automatically. Why? I don't know. But I saw a post way back near the beginning of this thread with a suggestion of how to block them completely, so I tried it and it worked.
Click on a message.
Click the 3 dots on the upper right.
Select BLOCK all.