Your company has an Exchange Server 2016 organization. The organization has a four-node database availability group (DAG) that spans two data centers. Each data center is configured as a separate Active Directory site. The data centers connect to each other by using a high-speed WAN link. Each data center connects directly to the Internet and has a scoped Send connector configured.
The company's public DNS zone contains one MX record.
You need to ensure that if an Internet link becomes unavailable in one data center, email messages destined to external recipients can be routed through the other data center.
What should you do?