Exchange Online - share calendar detail with external users

Question

Hi all,
Here my case: I setup an organization relationship between 2 tenants A and B , "Calendar free/busy information with time only" , "Everyone in your organization" and it works fine
'users at tenant A' can invite 'users at tenant B' to a meeting
'users at tenant A' can book 'room at tenant B' for a meeting
But they can view free/busy information with time only

I want 'users at tenant A' can view detail (Calendar free/busy with time, subject, and location) when they set schedule meeting for
'room at tenant B' without changing access level of organization relationship

'users at tenant B' can view calendar detail when they set schedule meeting , this is calendar folder permission that I set for a room at tenant B

Get-MailboxFolderPermission -Identity ******@mydomain.com:\Calendar  
  
FolderName           User                 AccessRights                                                               SharingPermissionFlags  
----------           ----                 ------------                                                               ----------------------  
Calendar             Default              {Reviewer}  
Calendar             Anonymous            {None}  
Calendar             Admin                {Owner}  

What shoud I do ? Please give me some advice, thank you very much.

Answer 1

Hi @Jack Chuong ,
I did a lot of tests and research to make the external cloud tenant user see my tenant's room mailbox calendar with details.
For this to work, in addition to applying the sharing policy, please have a check that calendar external sharing is enabled via Microsoft 365 Admin Center > Settings > Org Settings > Calendar > tick "let users share their calendars with people outside of your organization. And Allow" show calendar free/busy information with time, subject, location etc) .

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Answer 2

Hi @Jack Chuong ,

I would suggest that you could create a sharingpolicy to apply to this room mailbox to allow external users to see detailed free/busy information.
You could refer to the link to create this policy:
https://learn.microsoft.com/en-us/powershell/module/exchange/new-sharingpolicy?view=exchange-ps

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