Cannot share calendar with external person in Outlook for Mac

Copper Contributor



In a company with 2 different M365 tenants, I tried to share a calendar between 2 people from both tenants but without succes and with the following message:


"Outlook cannot open the folder, U don't have the permission to open this folder. Contact (user mailaddress) for further info"


What did I allready performed:


  • Under admin settings/organisation settings, I've checked the sharing settings for calendar, all fine.
  • Under exchange admin/ organizaton, I activated the 'organization relationship' on both tenants for each other.
  • On both Mac's I added the external user in the permissions to share the calendar  with the external user.


What am I doing wrong?









1 Reply



Any B2B or B2C setup between tenants?