Deny anonymous access , enabling only authenticated external/guest to join meetings

Mustapha365  - the question is whom were this meetings were sent to?

Confirm the steps you've perform to create this meetings.

1. Created a teams meeting and just added email address to the attendee?

2 Created Guest User in your tenant> Created a teams meeting and added those Guest user?

Anonymous Team meetings access was intended to cater #1:

https://docs.microsoft.com/en-us/microsoftteams/meeting-settings-in-teams#:~:text=Allow%20anonymous%20users%20to%20join%20meetings,-With%20anonymous%20join&text=To%20learn%20more%2C%20see%20Join%20a%20meeting%20without%20a%20Teams%20account.&text=Go%20to%20the%20admin%20center,users%20can%20join%20a%20meeting.

and I believe you shouldn't have any problem if you've added those attendee as B2B Guest User (External AAD or MSA) prior to adding them to the meeting.

- https://docs.microsoft.com/en-us/azure/active-directory/b2b/add-users-administrator

- https://docs.microsoft.com/en-us/azure/active-directory/b2b/user-properties#can-azure-ad-b2b-users-be-added-as-members-instead-of-guests

I hope this helps.

Polite as usual,

BFN

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