Make UnifiedGroupWelcomeMessageEnabled Work for Teams
Scenario: setting this setting to false to prevent a welcome message spamming a large group upon creation/addition then adding the members to the O365 Group via Exchange Admin Center - members do not receive welcome message as expected. Adding these members via Teams client - members DO receive the welcome message, and the setting is apparently ignored. This is bad because suggested group membership practice by Microsoft is as follows:
"Best practice for managing Teams members: Add and remove members from the Teams client to ensure that the correct cascading access control to other dependent cloud applications is applied. Additionally, you will avoid a disjointed experience leaving people with the impression they still have access to the resources they used to (until the next sync cycle either adds or revokes access to a particular component of the service). If you DO add or remove team members outside of the Teams client (by using the Office 365 Admin Center, Azure AD, or Exchange Online PowerShell), it can take up to two hours for changes to be reflected in Teams."
Scott Wheeler commented
I can confirm that is is still happening. Teams app is still not honoring the flag set. Disabling the welcome message via group and then adding Team members through Teams UI still results in a welcome message being received by the new member. If the member is added through powershell or azure-ad there is no welcome message sent.
Jason Cousineau commented
I just did some more digging regarding this issue. Apparently, if members are added inside of Teams they get the welcome message regardless of whether or not the UnifiedGroupWelcomeMessageEnabled setting is set to false. If members are added OUTSIDE of Teams via the Azure AD portal, O365 portal, the various O365, AAD, Exchange powershell cmdlets etc, then the UnifiedGroupWelcomeMessageEnabled setting IS honored, and since for Groups created IN Teams have that set to false by default, the new members do NOT receive a Teams welcome message NOR a legacy O365 Groups welcome message.
To sum it up – the Teams client does NOT honor the UnifiedGroupWelcomeMessageEnabled setting at all and sends a Teams-specific welcome message ONLY when members are added FROM Teams. Groups created in Teams have the UnifiedGroupWelcomeMessageEnabled set to false, so when members are added OUT of Teams they don’t get ANY welcome message.
This behavior is disjointed and confusing, especially for those people that are not savvy O365 admins that have extensively researched this behavior. Further, the fact that the welcome messages cannot be turned off completely (referring to the Teams-specific welcome message) is a problem. As an admin, I need to be able to set up Teams and Groups to have a unified, synchronous behavior across our organization no matter how members are added to a Group/Team.