Populate shared mailboxes into a dynamic M365 group

Question

Hi, all

Feel like I've been on Google searching this question for hours now...

Does anyone know how to dynamiclly add all organisation shared mailboxes into an M365 group?

So far, the only way I've found to do this is giving all shared mailboxes a custom attribute and then using the below to add them. However this does not automatically pull in future shared mailboxes without manually adding the attribute and defeating the purpose.

(user.extensionAttribute1 -eq "SharedMailbox")

If anyone had the rule syntax for adding all shared mailboxes that would be cool

Thanks

Answer 1

Thats not one of the allowed attributes you can use in Azure:

https://learn.microsoft.com/en-us/entra/identity/users/groups-dynamic-membership

However you can create an Exchange DDG that will do this based on RecipientTypeDetails

https://learn.microsoft.com/en-us/powershell/exchange/recipientfilter-properties?view=exchange-ps&preserve-view=true

Answer 2

Only on hybrid exchange
you can add in your AADsync the AD row "msExchRecipientTypeDetails"

https://learn.microsoft.com/en-us/answers/questions/1306903/how-to-sync-custom-attributes-from-ad-to-aad

Then create a EntraID Dynamic Group

(user.extension_############_msExchRecipientTypeDetails -eq 34359738368)

https://answers.microsoft.com/en-us/msoffice/forum/all/recipient-type-values/7c2620e5-9870-48ba-b5c2-7772c739c651