Sending, receiving, and organizing email in Outlook.com
Hi, R J Kimms
The missing “@” may mean the sender’s address is disguised rather than genuinely absent. In Outlook on the web, you can filter these messages using text in their message headers instead of blocking an address.
Here are some suggestions you can try:
Open one of the spam messages in your browser. Select the three dots at the top of the message, then View > View message details. Look for the From: line and check whether several spam messages share a distinctive name or text.
Select Settings > Mail > Rules > Add new rule and give the rule a name. Under Add a condition, choose Message header includes, then enter that repeated text.
Under Add an action, choose Move to, select a separate folder, and select Save.
I recommend reviewing that folder before switching to automatic deletion. Use distinctive text rather than generic words so you don’t accidentally filter legitimate email.