501275 – Microsoft Teams: Control External Access by Domain for Specific Users and Groups

Product:

Microsoft 365 Apps, Microsoft 365 Groups, Skype for Business, Teams

Platform:

Android, iOS, Mac, Web, Windows Desktop, World tenant

Status:

Rolling out

Change type:

Links:

MC1150123

Details:

Gain granular control over external communication. By setting custom External Access policies, you can define domain allow/deny lists and assign them to specific users or groups - capabilities that were previously tenant-wide only ("Teams and Skype for Business users in external organizations"). Use this to pilot with a department, restrict high‑risk roles to approved partners, or open federation broadly where appropriate. Example: Allow Group A to communicate only with a specific domain, while Group B can communicate with all external domains.

Change Category:
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Scope:
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Release Phase:
General Availability, Targeted Release

Created:
2025-08-27

updated:
2025-09-10

Docu to Check

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MS workload name

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summary for non-techies**

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Direct effects for Operations**

Please, look at the most relevant linked item for details

explanation for non-techies**

Imagine your office building has a security system that controls who can enter. Previously, the system allowed or denied access to the entire building based on a single rule: either everyone from outside could enter, or no one could. Now, imagine you can set specific rules for different floors or departments. For instance, the legal department can only be accessed by people from a specific law firm, while the marketing team can welcome visitors from any company.

This is similar to the new feature in Microsoft Teams, where you can now control external communication on a more detailed level. Previously, if you wanted to allow or block communication with external organizations, the setting applied to everyone in your company. Now, you can create custom rules for specific users or groups. For example, you might allow a particular team to communicate only with a trusted partner company, while another team can interact with any external organization.

This change provides more flexibility and security. It allows you to test new communication policies with a small group before rolling them out company-wide. It also helps protect sensitive roles by limiting their external interactions to approved partners. This is like having a customizable security system for your office, where you can decide who gets access to which areas, enhancing both security and efficiency.