MC267137: Microsoft Defender for Office 365: Creating allow URLs and Files in the Tenant Allow/Block List (TABL)

We understand that, from time to time, you might disagree with an Exchange Online Protection (EOP) filtering verdict. With this update, you will be able to override filtering verdicts using the Tenant Allow/Block List (TABL) in the Defender portal while your submission is being reviewed. This message is associated with Microsoft 365 Roadmap ID 70591.

One of the ways EOP protects customers is by blocking malicious attachments, URLs, and certain senders from reaching end users. We also understand that from time to time, customers may have special needs to block something on their own that our filters might find to be not malicious. In order to provide a way for our customers to do this at time of click and during mail flow, we’re developing a portal to help you self-serve and do it yourself. This portal will give admins the opportunity to explicitly allow or block attachments, URLs, senders and even certain recipients in your Office 365 tenant. This phase of this rollout enables explicitly allowing files and URLs.

MC267137: Microsoft Defender for Office 365: Creating allow URLs and Files in the Tenant Allow/Block List (TABL)

When this will happen

We will roll this out starting in early August and be complete by mid-October.

How this will affect your organization

Sometimes, a good message might be marked as bad (a false positive) or a bad message might be allowed through (a false negative).

The first step is to report the message to Microsoft via the Admin Submissions portal.

  • If you feel that you need to immediately allow the message, you can now choose to “Allow these types of messages” when submitting items that you believe should not have been blocked.
  • You will also see a new Sender tab in the Tenant Allow/Block List. Sender allows created during the submission process will be located here, as well as a place for you to add sender blocks.

To get started, open the Microsoft 365 Defender portal and go directly to the Tenant Allow/Block Lists page. See Learn more below for more detailed steps.

Learn more

Message ID: MC267137
Effective: August 2, 2021