How to differentiate between user mailbox and shared malbox from Microsoft Graph API explorer

Question

How to differentiate between user mailbox and shared mailbox from Microsoft Graph API explorer. I want to build app which should work with only shared mailboxes. Use of powershell is not possible due to limitation of basic authentication and we are not yet ready for modern authentication.

Answer 1

There seems not to be a way to differentiate shared mailboxes and normal user mailboxes with Microsoft Graph API explorer.

You could assign a keyword (like 'shared') as the givenName when creating shared mailboxes, or using the beta "findroomlists" outlook api endpoint.

See a similar post here.

Answer 2

There is finally a property available in Graph Beta for the MailboxSettings object to check this:

Properties

Property	Type	Description
userPurpose	userPurpose	The purpose of the mailbox. Used to differentiate a mailbox for a single user from a shared mailbox and equipment mailbox in Exchange Online. Read only.

Source: https://learn.microsoft.com/en-us/graph/api/resources/mailboxsettings?view=graph-rest-beta#properties