Exchange Hybrid Deployment Requirements

Question

We will migrate our on-prem mailboxes to exchange online. We are on Exchange 2013. We will have a 2019 hybrid server. Our Domain/Forest Functional Level is Windows Server 2012 R2. Our Domain Controllers are 2012 R2. We will upgrade our DCs after the migration because of compatibility issues with Exchange 2013.

Do we meet the requirements for having a 2019 Exchange Hybrid Server given our Level and DCs? I did read Microsoft's documentation., I want to make sure I did not misunderstand anything. Thank you.

Answer 1

Based on the information provided, it seems that your environment meets the requirements for having a 2019 Exchange Hybrid Server, as long as you meet the minimum version requirements for Exchange 2019 and have the necessary network and server infrastructure in place.

Here are some key requirements to consider:

• The minimum version of Exchange 2019 required for a hybrid deployment is Cumulative Update 1 (CU1) or later.
• Your domain and forest functional level must be at least Windows Server 2008 R2 or later, which is met by your Windows Server 2012 R2 functional level.
• You must have at least one writable domain controller running Windows Server 2008 R2 or later in each Active Directory site where you install the Exchange hybrid server, which is also met by your current environment.
• You need to ensure that your network infrastructure can support the hybrid deployment, including network ports, DNS resolution, and SMTP routing.
• You also need to ensure that your Exchange 2013 environment is properly configured for coexistence with Exchange Online during the migration.

As you mentioned, upgrading your domain controllers after the migration is a good approach to avoid any compatibility issues with Exchange 2013.

Answer 2

Hi @mara2021 ,

Your environment meets the requirements for having a 2019 Exchange Hybrid Server, you could refer to:

https://learn.microsoft.com/en-us/exchange/plan-and-deploy/system-requirements?view=exchserver-2019

For Best Practices for Migrating from Exchange Server 2013 to Exchange Server 2019, you could refer to this article:

https://techcommunity.microsoft.com/t5/exchange-team-blog/best-practices-for-migrating-from-exchange-server-2013-to/ba-p/3773084

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