Mailboxes

How to identify shared mailboxes with mailbox purpose data

Use mailbox purpose classification to separate shared mailboxes from regular user accounts without switching to a different toolchain.

5 min read Mar 28, 2026 Cengiz Yilmaz

Shared mailboxes often blur together with user identities when teams only look at a broad user export. M365 Tenant Reporter reads mailbox purpose so the snapshot can distinguish shared mailboxes from standard user mailboxes and other specialized mailbox types.

Why this matters

Mailbox type affects how teams reason about ownership, support, licensing expectations, and service desk workflows.

Practical review pattern

• Start with the shared mailbox count in the overview.
• Open the mailbox report to review detailed rows.
• Export the subset when ownership or cleanup work needs to happen outside the app.

Important caveat

If mailbox purpose is unavailable for a row, the app marks it as unknown instead of failing the entire collection run.