Identify the core features and objects of Microsoft 365 services
Exchange, SharePoint, and Teams Objects
ImportantChoose the right messaging, collaboration, storage, role, and policy object without confusing closely connected Microsoft 365 services.
Aligned to the current AB-900 guide, verified July 22, 2026.
Why this matters
AB-900 tests whether you can choose the right collaboration object and trace access across Exchange, SharePoint, and Teams without confusing storage, membership, and policy.
Must Know
- A user mailbox stores one person’s mail; a shared mailbox stores team mail with delegated access; a distribution group delivers copies but has no shared inbox.
- A Microsoft 365 group supplies collaboration membership and shared resources; a distribution group is primarily for email delivery.
- A team is the broad collaboration and membership boundary; channels organize work inside it and can have different membership by channel type.
- SharePoint hierarchy is site → document library → folder → file. The site is the usual collaboration boundary; a library is a managed content container.
- Owners administer, Members contribute or edit, and Visitors read. Grant the least privilege that satisfies the task.
- Teams policies control Teams capabilities, but SharePoint permissions still control channel files and Exchange permissions still control recipients.
Compare and Distinguish
- User mailbox vs shared mailbox vs distribution group: personal stored mail vs delegated common stored mail vs message delivery to members.
- Microsoft 365 group vs distribution group: collaboration membership with shared resources vs primarily email distribution.
- Team vs channel: a team is the broader membership/collaboration boundary; channels organize work inside it and may have distinct membership depending on channel type.
- Site vs library vs folder: collaboration/permission boundary vs managed document container vs organizational path within a library.
- Owner vs Member vs Visitor: administer/control vs contribute/edit vs read; choose the least privilege that satisfies the task.
Scenario examples
- Scenario: Support needs help@contoso.com with several people reading and replying as that address. Think: Use a shared mailbox with the required mailbox and send permissions.
- Scenario: Executives need announcements delivered by email but no shared workspace. Think: Use a distribution group.
- Scenario: A Teams channel member cannot open a cited file. Think: Identify the channel type and connected SharePoint storage, then inspect effective permission rather than changing a meeting policy.
- Scenario: Contractors should read a project site but not edit it. Think: Place them in the appropriate Visitors-style group instead of making them site Owners.
Exam traps
- A distribution group has no shared mailbox history or SharePoint workspace.
- A Microsoft 365 group and a team are related, but the team adds Teams experiences and policies; the terms are not synonyms.
- A library is inside a site and can hold folders; it is not a tenant-level peer of a site.
- A Teams policy cannot grant access to a SharePoint file, and a SharePoint role cannot enable a Teams meeting feature.
Key takeaways
- Mailbox stores mail; shared mailbox stores common mail; distribution group distributes mail.
- Team → channels; connected SharePoint site → libraries → folders/files.
- Owners manage, Members contribute, Visitors read; workload policy and content permission solve different problems.
How it works
- Microsoft 365 group membership connects people to shared resources. Teams uses that collaboration foundation, while Exchange and SharePoint retain their own object types and administration.
- SharePoint permission inheritance normally flows from site to library, folder, and file. Unique permissions or sharing links create additional paths that must be evaluated when effective access differs from expectations.
- A shared mailbox separates the shared mail identity from individual delegates. Full Access permits opening/managing the mailbox, while Send As or Send on Behalf controls how outgoing messages identify the sender.
Objects and administrative surfaces
- User and shared mailboxes, distribution groups, delegation, and mail flow — Exchange admin center.
- Sites and tenant sharing/access policies — SharePoint admin center; libraries, folders, files, links, and most content permissions — SharePoint site experience.
- Teams, channels, apps, users, and meeting/messaging/calling policies — Teams admin center and Teams client.
- Microsoft 365 groups and their owners/members — Microsoft 365 admin center or Microsoft Entra admin center, with workload-specific settings in the workload surface.
When to use it
- Use a shared mailbox for a managed common address, a distribution group for email broadcast, and a team for ongoing group collaboration.
- Use a SharePoint library when documents need metadata, views, versioning, and managed access; use folders only as one organization layer inside it.
- Use Teams policies to govern Teams capabilities and SharePoint permissions to govern channel-file access.
Security and governance implications
- Prefer managed groups and default site roles over many direct file grants; review owners because owners can expand access.
- Use private or shared channels only when the membership distinction is required and include their separate storage in lifecycle and access reviews.
- Grant shared-mailbox and send permissions deliberately, and audit changes to high-value recipients and sites.
Troubleshooting signals
- Identify the object first: mailbox, group, team, channel, site, library, folder, or file. Then inspect that object’s membership, permission inheritance, policy, and service health.
- For a shared mailbox, check mailbox existence, delegate assignment, Full Access, Send As/Send on Behalf, and client refresh or propagation.
- For channel files, locate the associated SharePoint site, check channel membership, group membership, sharing links, and unique permissions.
More detail
- A user mailbox is associated with a user and stores that person’s mail. A shared mailbox gives a team a common address and mailbox; delegates need the appropriate read/manage and send permissions. A distribution group expands a message to members but provides no shared inbox or document workspace.
- A Microsoft 365 group supplies membership and shared resources that can include a group mailbox, calendar, and SharePoint site. Creating a team commonly uses a Microsoft 365 group and adds Teams conversations, channels, meetings, apps, and policies.
- A SharePoint site is the collaboration and permission boundary. A document library is a managed collection inside the site, a folder organizes content inside a library, and files are the content. Libraries can have columns, views, versioning, and policies that ordinary folders do not define independently.
- Teams standard-channel files are stored in the connected team SharePoint site. Private and shared channels have distinct membership and storage behavior, so channel membership and its associated site both matter during access troubleshooting.
- Default SharePoint site groups express simple roles: Owners administer the site and typically have Full Control, Members contribute or edit content, and Visitors read. Site administrators can have broader authority; avoid granting ownership merely to solve a read problem.
- Teams policies control capabilities such as meetings, messaging, apps, and calling for assigned users. A Teams policy changes what users can do in Teams; it does not replace SharePoint file permissions or Exchange recipient permissions.
Ready for the quiz?
- When should you choose a shared mailbox instead of a distribution group?
- How do a SharePoint site, library, and folder differ?
- Why might a Teams member still be unable to open a channel file?
- Which default SharePoint role fits read-only access?
Related objectives
- D1.1.c — Identify the appropriate objects to configure by using the Exchange admin center (mailboxes and distribution groups)
- D1.1.d — Identify the appropriate objects to configure by using the SharePoint admin center (sites, libraries, and folders)
- D1.1.e — Identify the appropriate roles and permissions for sites in SharePoint in Microsoft 365
- D1.1.f — Identify the appropriate objects to configure by using the Teams admin center (teams, channels, and policies)