You administer two Microsoft SQL Server 2012 servers. Each server resides in a different, untrusted domain. You plan to configure database mirroring. You need to be able to create database mirroring…

Configuring the SQL Server service account to use Network Service relies on Windows authentication, which is not supported across untrusted domain boundaries for database mirroring.

When SQL Server instances are in untrusted domains, server certificates are the necessary mechanism for authenticating the database mirroring endpoints because Windows authentication cannot span these untrusted boundaries. These certificates establish trust and encrypt the communication channel between the mirroring partners, allowing the endpoints to be created and function securely.

Database certificates are typically used for encrypting database content or signing objects within a database, not for authenticating server-to-server connections like database mirroring endpoints.

The Local System account lacks network credentials and cannot authenticate across the network, making it unsuitable for establishing database mirroring endpoints.