By Sergiu Gatlan
Publication Date: 2025-12-24 16:22:00
Microsoft announced that security administrators will soon be able to block external users from sending messages, calls, or meeting invitations to members of their organization via Teams.
The new feature will start rolling out in early January, integrating Microsoft Teams with Defender for Office 365, and enabling admins to manage blocked external contacts through the Tenant Allow/Block List in the Microsoft Defender portal.
It will work across the Defender XDR web portal, and all Teams clients, and the update will not change existing domain blocks or federation configurations in the Teams admin center.
Before using the feature, organizations must enable two settings in the Teams admin center, which are disabled by default: “Block specific users from communicating with people in my organization” and “Allow my security team to manage blocked domains and blocked users.”
Once enabled, it will allow security admins with Teams permissions to add, delete, and view…
