A transit authority needs a shared mailbox so overnight emergency-management staff can send and receive from one common address. Which admin center is the correct place to create that mailbox object?

A transit authority shared mailbox used by overnight emergency-management staff is an Exchange Online recipient object. The correct place to create that mailbox is the Exchange admin center, where shared mailboxes are provisioned so multiple people can send and receive from one common address without each person needing a separate licensed user mailbox dedicated to that address. Shared mailboxes fit municipal duty desks that need continuity across shifts.

SharePoint admin center fails by concept because it governs sites, libraries, and content services—not Exchange mailboxes. A document library is not a shared mailbox. Teams admin center fails because it administers teams, channels, policies, and related collaboration settings; creating a Team or channel does not create an Exchange shared mailbox object for a common SMTP address. Microsoft Purview compliance portal fails because Purview focuses on data protection, auditing, retention, and compliance workloads; it does not provision mailbox recipients for emergency dispatch mail.

Exam caveat: AB-900 repeatedly maps object types to admin centers. Shared mailbox equals Exchange. Do not confuse ‘shared’ collaboration language with SharePoint sharing or Teams shared channels when the stem clearly asks for a mailbox object.

Operational check: in Exchange admin center, create the shared mailbox on a verified city domain, grant Full Access (and Send As if required) to overnight emergency-management staff or a security group, confirm the address appears in the global address list as intended, and have two shift accounts send and receive a test thread from the common address before declaring the desk live.