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stevecousins's avatar
stevecousins
Copper Contributor
Jan 05, 2021
Solved

External Guests being invited to channel meetings

When I create a new channel meeting and invite specific members of the channel, the invite is created and the attendees receive the meeting notification, however, external guests who are members of t...
meetings
microsoft teams
  • candera's avatar
    candera
    Aug 29, 2022

    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.

HeinzelAlex's avatar
HeinzelAlex
Copper Contributor
Feb 24, 2023

candera 

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? 

candera's avatar
candera
Brass Contributor
Feb 24, 2023
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.

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