Will Exchange work without AD or without DC?

Question

System administration

Will Exchange work (at least receive mail) if AD or DC are temporarily unavailable, provided that the Internet is available on Exchange itself? The process itself is not clear when receiving / transmitting messages, what it refers to.

Answer 1

Will.
User authorization in Exchange will be difficult. Receiving external letters does not affect at all, the SMTP agent works there without AD

Answer 2

yes, it will (sometimes it happened to me at work)

Answer 3

Will not. All exchange data is stored in active directory. For example, information about users, and about the database in which the mailbox is located.