Teams users will now see an invitation pop-up to accept or block an external user when receiving new chats from external users.
This message is associated with Microsoft 365 Roadmap ID 94646
When this will happen:
We will begin rollout for this feature in mid-August and expect rollout to be completed by early September.
How this will affect your organization:
When receiving a new one-on-one chat from an external user, Teams users will receive an invitation to accept or block the external user. This also provides the ability to block external users at any point, which revokes access to presence and incoming messages.
What you need to do to prepare:
There is nothing you need to do to prepare for this change. You may want to notify your users about this change and update your training and documentation as appropriate.