Background: Microsoft offers no REST API for accessing the access rights of shared mailboxes, which means that it is impossible to know which users are allowed to access shared mailboxes through Microsoft Graph API. However, there is a way to introduce this data to amberSearch, enabling all amberSearch users to search through shared mailboxes easily.
We have published a PowerShell script that establishes a connection with the online Exchange Servers of Microsoft and retrieves the mappings between the shared mailboxes and the users, who have access to them. You can find it here https://github.com/ambersearch/Tools/tree/main/Office365/Outlook
- You should own an administrator account in Microsoft to expect the desired output
- The powershell script generates a .csv file. Please send the file to the amberSearch team