Hiding Office 365 Groups Created by Teams from Exchange Clients

PhilHemingwaySTV I'm sure that every team does turn up in the GAL, but only if an action is taken to update its HiddenFromExchangeClientsEnabled property. All teams created through team-aware admin interfaces set this property to $False. If you create using an ISV app, PowerShell, or some Graph-enabled app, you might find that the property is set to $True. For instance, even Teams sets the property to $True for the special team it creates to control who's allowed to create approvals templates. But the general point holds true: teams created through Teams set HiddenFromExchangeClientsEnabled to $False.

Teams doesn't appear in an address list like other mail-enabled objects unless its Office 365 Group is not hidden from the lists, so it is hard to know when private teams are available. Public teams can be found by the Join or Create a team option, which presents a list of suggested public teams available to the user. The search function on the same screen can be used to find other public teams that don't make the suggested list, which is determined by reference to signals in the Graph. Private teams don't appear in suggestions, so the only way to join them is to contact the team owner (how you learn about the existence of the team is another matter - perhaps via a coffee room conversation?).

As I say in the piece, the change is rolling out... and while the change is effective in the back-end (i.e. you can set groups to be hidden from Exchange clients now), some client updates are also necessary. These will come in OWA and Outlook (to respect the flag) and Teams (to set the flag). Don't be so impatient.

As to ordered hash tables, I used these a lot to capture Office 365 data with PowerShell. Once in the hash table, you can do so much with data... as proven here.