Exchange Online Architecture Overview
Understanding the Concept
Exchange Online is Microsoft's cloud-based email and calendaring service, part of the Microsoft 365 suite. It provides enterprise-grade messaging capabilities without requiring on-premises Exchange Server infrastructure.
The architecture consists of multiple layers: the transport pipeline handles mail flow, the mailbox database stores messages, and the Client Access services handle connections from Outlook, OWA, and mobile devices.
Exchange Online leverages Azure Active Directory for authentication and identity management, integrating seamlessly with other Microsoft 365 services like Teams, SharePoint, and OneDrive.
Key Points
Exchange Online Architecture
Azure AD
Identity & authentication layer
Transport Pipeline
Mail flow processing & rules
Mailbox Database
Message storage & indexing
Client Access
Outlook, OWA, Mobile, IMAP
Why This Matters
Understanding Exchange Online architecture is fundamental for troubleshooting mail flow issues, planning migrations, and designing hybrid configurations. Administrators must know how components interact to effectively manage the messaging environment.