Exchange Online Not Blocking the Email Even After Restricting from the AntiSpam Filter

Scenario:

As an IT/ Global Admin, you block a domain, sender, or IP address in Spam Filter configuration but the emails are still coming in which are not supposed to be.

Resolution:

Here are the steps to block a domain/ sender completely:

• Access the URL with the Global Admin account: https://security.microsoft.com/tenantAllowBlockList 
• Now, Click on the block button and create a new block policy as shown in the below screenshot:

• Add the domain and senders email account as per the required parameter in the below screenshot: