Shadow redundancy in Exchange Server.

[robopet3]

Shadow redundancy in Exchange Server.
https://docs.microsoft.com/en-us/exchange/mail-flow/transport-high-availability/shadow-redundancy?view=exchserver-2019

Queues and messages in queues in Exchange Server
https://docs.microsoft.com/en-us/exchange/mail-flow/queues/queues?view=exchserver-2019