Recommendations for Building a DR Site for MS Exchange 2019 Setup

Question

I’m seeking recommendations for setting up a disaster recovery (DR) site for our Microsoft Exchange 2019 environment. Below is a brief overview of our current setup:

Current Setup:

• We have MS Exchange 2019 servers hosted in our HQ main datacenter.

Around 2100 mailboxes are registered and part of a Database Availability Group (DAG).

We have four identified mailbox quotas for end users (5 GB, 10 GB, 15 GB, and 20 GB).

Fortinet FortiMail email gateway is in use to secure incoming and outgoing mail, with advanced malware detection and sandboxing for email attachments.

Email services are hosted on 3 virtual servers, integrated with Active Directory for authentication and identity verification.

Management’s Request:

We need to build a DR site to ensure business continuity for our Exchange services.

Questions:

What would be the best approach for setting up a DR site for Exchange 2019, particularly in terms of DAG replication and failover?

How can we ensure proper synchronization and minimal downtime in case of an emergency or server failure?

Are there any specific best practices or tools for integrating FortiMail and email security in a DR setup?

Should we consider any additional redundancy or failover mechanisms for the virtual servers, Active Directory, and other dependencies?

What are the potential challenges we should be aware of when implementing a DR solution for Exchange?

I’d appreciate any advice on best practices, tools, or strategies to build a robust DR environment for our Exchange setup. Thanks in advance!