Which feature helps in controlling the flow of incoming and outgoing messages in Exchange?

The feature that aids in controlling the flow of incoming and outgoing messages in Exchange is Transport Rules. Transport Rules allow administrators to define specific conditions under which certain actions are executed on messages as they pass through the mail transport system. For example, organizations can set rules that block certain types of attachments, redirect messages based on sender or recipient, and apply disclaimers to outgoing emails. This capability is essential for managing compliance, regulating content, and enforcing organizational policies related to email communications.

Mailbox Permissions pertain to the ability of users to access and manage mailbox data, while Calendar Assistant focuses on scheduling and managing meetings and appointments. Audit Logging serves to track changes and access to data within Exchange, but does not actively manage or control message flow. Therefore, Transport Rules stands out as the primary mechanism for message flow control.