Using classic Outlook for Windows in business environments
Hello CedBri
Hi, I'm Karl and will be happy to help you today.
Since you posted your question in the Outlook desktop (part of Office) forum
Are you adding this sender to the Blocked Senders List in the Outlook desktop program or in the Junk email settings after logging into the Outlook.com account via webmail (using a browser)?
If you add this sender to the <Blocked Senders> list on the server - does the problem remain?