Allow only specific external domains

Hi,

External Access and Anonymous meeting access are two different configurations in Microsoft Teams, and they affect different scenarios. External Access controls federation (1:1 chat, calls, presence) between organizations. It does not control how users appear inside a meeting. Meeting join behavior is governed by meeting policies and lobby/anonymous settings.

Here is how your scenarios work in practice.

Scenario 1
If External Access is set to “Allow only specific external domains” and a user from a domain that is not on the allowed list joins a meeting while signed in with their work account, they can still join the meeting (assuming meeting settings allow external authenticated users).

They will appear with their actual display name, and typically their organization label (External). They will not appear as Anonymous simply because their domain is not in the External Access allowed list.

This is because joining a meeting as an authenticated Azure AD / Entra ID user is different from federation. External Access restrictions block chat and calling federation, not meeting participation.

Scenario 2
If a user from a non-allowed domain joins through the browser and selects “Join as guest” without signing in, they are treated as an unauthenticated participant.

They will appear with whatever name they manually enter. They will not automatically show as “Anonymous.” In the participant list they are shown as an anonymous user, but with the display name they typed.

Again, this behavior is not driven by the External Access setting, but by whether the user is authenticated.

Scenario 3
If a user joins without authenticating and the meeting policy allows anonymous access, then yes — they will be treated as an anonymous participant. In this case, their identity is not verified, and their presence in the meeting is governed by anonymous access settings and lobby configuration.

This is unrelated to the External Access restriction. External Access only controls cross-tenant federation (chat, calls, presence), not anonymous meeting joins.

Summary

– External Access “Allow only specific domains” impacts federation, not meeting identity display.
– Authenticated users (even from non-allowed domains) appear with their real name and organization when joining meetings.
– Browser “Join as guest” users appear with the name they type.
– Anonymous appearance is controlled by meeting policies, not External Access settings.

So yes, your understanding in all three scenarios is essentially correct, with the key clarification that meeting behavior is independent from the External Access federation restriction.

What I want to know is With “Allow only specific external domains”, if a person from a non-allowed domain will typically join as Anonymous (if anonymous join is enabled) or will he join as Username because we plan to disable anonymous.