Hello!
It appears an organization (with DirSync) cannot create both a "Mail Contact" (in on-prem AD) and a "SPO Registered External User" with the same email address.
You get a honkin' "Identity Synchronization Error".
What gives? Anyone experience this before.
I think I get it: two accounts in the same "Azure AD" cannot have the same proxy attribute - and both MailContact & ExternalUser are stored there... but what happens when you WANT to have a Mail Contact registered as an SPO External User?
Thanks for being here!
Joe
