Outlook not blocking a domain set up as blocked sender

Question

I have set a domain as a Blocked Sender about 3 weeks ago, and yet I still receive junk mail from that domain. Does this blocking really work or is there another way other than the cursed rules

Answer 1

Dear Anthony Ogilvie,

Thank you for posting to the Microsoft Q&A. I understand that you are looking for a way to permanently stop junk mail from a specific domain, especially since the standard "Block" function doesn't seem to be effective.

As Hornblower409 correctly mentioned, the "Blocked Senders" tool is technically designed only to route emails to the Junk Email folder, not to bounce them or stop them from entering your mailbox entirely.

Furthermore, if these emails are still hitting your Inbox despite the block, it is likely that sophisticated spammers are "masking" their true email address behind the scenes, so the standard Block list doesn't recognize them.

I know you referred to rules as 'cursed'—and I completely understand that sentiment. However, to stop this permanently, we must set up a specific 'Hard Delete' rule. This is a one-time configuration that ignores the spammers' masking tricks and checks the visible text instead, deleting the mail before it ever bothers you.

Here is how to set up the "Auto-Delete" Rule: 

• Right-click one of the junk emails from that domain.
• Select Rules > Create Rule.
• Click Advanced Options.
• Step 1 (Condition): Check the box "with specific words in the sender's address".
• Click the blue underlined link "specific words" at the bottom.
• Enter the domain (e.g., bad-domain.com) and click Add, then OK.
• Step 2 (Action): Click Next. Check the box "move it to the Deleted Items folder" (or "permanently delete it" if you are sure).
• Click Finish.

I hope setting up this specific filter finally stops those domains from cluttering your view. If you have any updates regarding the issue, please feel free to share them with me.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.      

Answer 2

If you've set a domain as a Blocked Sender in Outlook and are still receiving junk mail from that domain, there are a few things to consider:

1. Propagation Time: Sometimes, it may take a little while for the block to take effect fully. If it's been three weeks, this shouldn't be the case, but it's worth noting.
2. Specificity of the Block: Ensure that you have entered the domain correctly. For example, blocking @example.com will block emails from that domain, but if the sender uses a subdomain (like newsletter.example.com), you may need to block that specifically as well.
3. Outlook Settings: Check if there are any other rules or settings that might be allowing those emails through. Sometimes, rules can conflict with the Blocked Senders list.
4. Use of Anti-Spam Policies: If multiple users are affected, consider using blocked sender lists or blocked domain lists in custom anti-spam policies, which can provide a more comprehensive solution.
5. Tenant Allow/Block List: For organizations using Microsoft 365, you can also use the Tenant Allow/Block List to block domains at a higher level, which can be more effective than individual mailbox settings.

If the issue persists, you may want to explore these options further or consult with your IT administrator for additional assistance.

---

References:

• Create sender blocklists for cloud mailboxes
• Allow or block email using the Tenant Allow/Block List