Supported co-existence for Exchange 2019
- Exchange 2010, not supported
- Exchange 2013, supported with 2013 CU21 or later, including Edge Transport Servers
- Exchange 2016, Supported with 2016 CU11 or later, including Edge Transport Servers
- Mixed 2013 and 2016, Supported if 2013 and 2016 meeting previous requirements
Network and directory server requirements for Exchange 2019
- Domain Controller, Windows Server 2012 R2, 2016,2019
- AD Forest, Windows Server 2012 R2 or higher
- AD Site, Writable domain controller and global catalog server
- DNS Namespace, Contiguous, Non-contiguous, Single label domain, Disjoint.
- IPv6, Exchange 2013 or later supports IPv6 when installed and enabled; send and receive in IPv6 if supported
References:
https://docs.microsoft.com/en-us/exchange/plan-and-deploy/system-requirements?view=exchserver-2019
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