Exchange 2019 Certificate Error

Hello! Neymar​ 

The certificate name mismatch occurs because the newly added Exchange Server 2019 is being accessed directly by users' Outlook clients.

To resolve this issue, block inbound TCP port 443 traffic from client networks to the Exchange Server 2019 IP address at the firewall level.

This will prevent direct client connections to the backend server and ensure that Outlook connects only through the designated load balancer or Client Access endpoint.