Microsoft Teams now integrates with Microsoft Defender for Office 365 Tenant Allow/Block List, enabling security admins to centrally manage blocked external domains in Teams. This feature, rolling out from August to October 2025, allows blocking communications, deleting existing messages, and auditing actions, with admin controls managed via Teams and Entra ID.| mc.merill.net
Learn how to manage cross-tenant access in Microsoft Entra External ID. Configure B2B collaboration and direct connect settings to control access and trust for external organizations.| learn.microsoft.com
