It is recommended to enable Datacenter Activation Coordination (DAC) mode for Exchange database availability groups that meet the criteria.
Introduction to Exchange Server 2016 Database Availability Groups
Getting started with Exchange Server 2016 high availability by learning the fundamental concepts of database availability groups.
Datacenter Activation Coordination Mode
An overview of Datacenter Activation Coordination Mode and how it prevents split brain conditions in Exchange Server database availability groups.
Are Lagged Database Copies a Waste of Time?
Are lagged database copies in Exchange Server 2013 a useful feature or a waste of time and storage?
PowerShell Tip: List Active Mailbox Database Copies for an Exchange Server Database Availability Group
How to use PowerShell to list details of the active mailbox database copies in an Exchange Server database availability group.