Hello @NathanC ,
Thank you for reaching out to Microsoft Azure QnA platform. I would like to confirm that “Identities” is a read-only property in Microsoft Entra External ID indicates the user’s primary identity provider. A user can have several identity providers, which can be viewed by selecting the link next to “Identities” in the user’s profile or by querying the identities property via the Microsoft Graph API.
More details about the differences can be found on following screen clipping from following article: https://learn.microsoft.com/en-us/entra/external-id/user-properties
Identities can also show up mail when user does not exist on any Azure AD Tenant and uses mail OTP method to verify identity and accept the invite.
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