Exchange 2013 to Exchange Online migration and Exchange 2019 co-existence

Nicholas Palmer 81 Reputation points


I've got an environment running Exchange 2013 CU23 servers running on Windows Server 2012 R2 that I am going to be migrating to Exchange Online. As I have to keep an Exchange server around to manage the Exchange user properties (we will continue to us AD Connect), I was going to bring up a new Exchange 2019 server running on a new Windows Server 2019 server so that I can be running the latest Exchange and when done with the migration to Exchange online, decommission the Exchange 2013 servers.

My question is when should I consider adding the new Exchange 2019 server to my environment? Should I add the new Exchange 2019 server before I start the migration process to Exchange Online, or after the migration to Exchange Online is complete?

Any suggestions would be very helpful.

Thanks in advance,

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
7,390 questions
Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
1,915 questions
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Accepted answer
  1. Andy David - MVP 142.7K Reputation points MVP

    Yes, everything but Step 5 if you no longer have mailboxes nor public folders on-prem
    Otherwise, thats it!

2 additional answers

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  1. KyleXu-MSFT 26,211 Reputation points

    @Nicholas Palmer

    Both are ok.

    But I would suggest you deploy Exchange 2019 coexist with Exchange 2013 first, then configure Exchange 2019 as Internet facing server, then begin to create hybrid and migrate to Exchange online. Because in this way, you will not need to change the Internet server and hybrid endpoint.

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  2. Andy David - MVP 142.7K Reputation points MVP

    I personally would just move all the mailboxes to Exchange online first via 2013, then bring up the 2019 server afterwards and run the Hybrid Wizard against 2019 then..
    That way , no issues that you will mess anything up :)