The MS-203 Microsoft 365 Messaging Administrator Certification Transition Exam evaluates the expertise of individuals who have already obtained an Exchange Server certification. The test gauges a candidate's aptitude for controlling, monitoring, and troubleshooting Microsoft 365's communications infrastructure. The test questions ask on a variety of subjects, including as migration, compliance, security, and mail flow. The ability to configure, manage, and troubleshoot Exchange Online, Exchange Server hybrid systems, and Office 365 message security are requirements for candidates.