Forum Discussion
External Guests being invited to channel meetings
ongrieh , stevecousins I have been chasing this problem as well. What I have figured out is that behind the scenes of the Team is a MS365 group and all Guest Users are automatically designated as 'Subscribers' of the group, regardless of team setting on "AlwaysSubscribeMembersToCalendarEvents" and "AutoSubscribeNewMembers". I presume this is because they can't directly interact with the Team/Group and self-subscribe or join channel meetings ad-hoc. However, this is not ideal because guests then get invited to _every_ channel meeting without explicitly inviting them.
The only way I can find to remove guests as subscribers is via PowerShell. You can view group/team Subscribers with Get-UnifiedGroupLinks -Identity [team name] -LinkType Subscribers. You should see the Guest accounts listed as 'MailUser' recipient types with #EXT# on the name. You can remove these with Remove-UnifiedGroupLinks -Identity [team name] -LinkType Subscribers -Links [Name]. Allow a few moments for the subscriber list to update.
This does not remove guests from their Member role, but now they won't be email-invited to every channel meeting. I haven't confirmed it yet, but it is possible that Guest Accounts get re-subscribed from some unknown trigger. That plus additional guests getting auto-subscribed necessitates creating a script to routinely unsubscribe guests.
Microsoft should fix Teams to honor "AlwaysSubscribeMembersToCalendarEvents" and "AutoSubscribeNewMembers" on Guest accounts.
stevecousins I totally agree. Tiago Roxo you did not quite get the whole picture of the problem and its consequences here 😉
Especially the way the system behaves differently between users of the own and users of a different organization (so called "Guest").
ongrieh , stevecousins I have been chasing this problem as well. What I have figured out is that behind the scenes of the Team is a MS365 group and all Guest Users are automatically designated as 'Subscribers' of the group, regardless of team setting on "AlwaysSubscribeMembersToCalendarEvents" and "AutoSubscribeNewMembers". I presume this is because they can't directly interact with the Team/Group and self-subscribe or join channel meetings ad-hoc. However, this is not ideal because guests then get invited to _every_ channel meeting without explicitly inviting them.
The only way I can find to remove guests as subscribers is via PowerShell. You can view group/team Subscribers with Get-UnifiedGroupLinks -Identity [team name] -LinkType Subscribers. You should see the Guest accounts listed as 'MailUser' recipient types with #EXT# on the name. You can remove these with Remove-UnifiedGroupLinks -Identity [team name] -LinkType Subscribers -Links [Name]. Allow a few moments for the subscriber list to update.
This does not remove guests from their Member role, but now they won't be email-invited to every channel meeting. I haven't confirmed it yet, but it is possible that Guest Accounts get re-subscribed from some unknown trigger. That plus additional guests getting auto-subscribed necessitates creating a script to routinely unsubscribe guests.
Microsoft should fix Teams to honor "AlwaysSubscribeMembersToCalendarEvents" and "AutoSubscribeNewMembers" on Guest accounts.
Which permissions are needed to execute the PowerShell script? Is this something only the IT can do or can this been executed by a teams owner?
- As Steven noted it does require some Exchange permissions. You can return a list of all Roles that can run an Exchange PS command as outlined here: https://learn.microsoft.com/en-us/powershell/exchange/find-exchange-cmdlet-permissions?view=exchange-ps There are a number of non-admin roles that could be used.
Microsoft has since added "Shared Channels" which I recommend looking at for any partners you may collaborate regularly with. These allow you to add External MS users as members of a channel and the channel will appear in their native organizations team, without having to switch to a guest account. I haven't tested, but it's possible this setup would honor the Disable AlwaysSubscribeToCalendarEvents flag. HeinzelAlex It's not possible to do with Team Owner rights, needs some Exchange Admin permissions.
Very same issue here. Thanks for posting the workaround. Have you confirmed if the guests get re-subscribed?
I'm also weighing up what is the biggest headache, having to tell the guests not to join the meetings or removing notifications from them altogether, meaning they will potentially miss conversations they are tagged in. Would be interested to hear your experience with this?
iamatechpm - The guest account has not been re-subscribed, which is good news. I think I wasn't tracking some testing very well and was fooled into thinking it might have happened.
I think removing the subscription is the best action. Telling someone to ignore may end up with missed meetings they were intentionally invited to and still joining meeting they don't need to. These have both happened to me with my guest account.
I did test that channel mentions and @ mentions will still show on the guest account in teams.
