How to block email domains or addresses.

TPAT, being such a large organisation, often receives emails from unscrupulous actors seeking to do harm, or to exploit naivety for financial gain. This guide is to show how to block addresses or domains to prevent our colleagues from receiving an assortment of threats, ranging from phishing emails, malware, or social engineering attempts.

1. Navigate to https://security.microsoft.com/.
2. On the left-hand menu, click on "Policies & rules".
3. Click on "Threat policies".
4. Click on "Tenant Allow/Block Lists".
5. Press the "Block" button, indicated by a large plus sign.
6. Enter the domains or addresses. For domains, the asterisk wildcard is not required.
7. Choose how long the block entry should remain in place for. It is recommended to set the entry to "Never expire".
8. In the "Optional note" section, it is good practice to put the reason for blocking, as well as the ticket number (if applicable).
   • Optional note example: "Suspected trojan, caught by antivirus | Ticket #12345".
9. Click add at the bottom.

Please watch the attached video for a visual guide.