M365 Copilot Chat — What It Actually Sees

Licence required before you start

The features in this guide require the Microsoft 365 Copilot paid add-on. They are not available on standard M365 plans (E3/E5) or free Copilot Chat (except Copilot Chat within Outlook, which retains inbox and calendar grounding for all users). Verify your licence under Settings → Subscriptions or contact your Microsoft admin or check your organisation's licence portal.

What each tier can access

Data source	Free (E3/E5 included)	M365 Copilot paid add-on
Outlook email (received)	Copilot Chat in Outlook only · inbox grounding · standalone Chat has no access	Up to 10 results per query · recency-weighted
Outlook calendar	Copilot Chat in Outlook only · calendar grounding · standalone Chat has no access	Yes — meetings, invites, attendees
Teams chat messages	No access	Last 30 days · current thread only (in Teams app)
Teams channels	No access	Channels you are a member of only
OneDrive files	No access unless you upload the file manually	Yes — files you have access to · @mention to reference explicitly
SharePoint documents	No access	Yes — sites and files your permissions allow
Meeting transcripts (Teams)	No access	Yes — meetings you attended where transcription was enabled
Web (Bing search)	Yes — primary data source	Yes — Web/Work toggle controls which is queried
Files uploaded to chat	Yes	Yes
Copilot Notebooks	No access	Yes — grounded in references you pinned
SAP · Primavera · external systems	No access	No access without a custom connector. Federated connectors for third-party apps (Canva, HubSpot, Notion, Linear) in Public Preview as of February 2026.

How to confirm which tier you have: open Copilot Chat. If you see a Web / Work toggle in the interface, you have the paid add-on. If you see web results only with no toggle, you are on the free tier.

How the permission model works

Your identity, your data

Copilot queries Microsoft Graph using your identity. It can only retrieve content you already have permission to access. No new access is created. If you cannot open a SharePoint file, Copilot cannot see it either.

Permissions are enforced at retrieval

The semantic index that powers Copilot retrieval enforces your access controls at query time, not at index time. Content is filtered before it reaches the model — the model never "sees" data it could not surface to you.

Sensitivity labels are respected

Emails and files encrypted with Purview sensitivity labels are subject to usage rights. If your rights do not include content extraction, Copilot will not surface that content even if you can open the file.

Overshared content is visible

Copilot surfaces everything your permissions allow — including files shared too broadly. If a SharePoint site grants view access to everyone in the organisation, Copilot can retrieve its content for any user. This is a governance issue, not a Copilot issue.

Why two people get different answers to the same prompt

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Different email and Teams histories

Each user's Copilot query runs against their own inbox, their own Teams threads, their own calendar. If User A is on a project email chain and User B is not, they return different results from identical prompts. This is correct behaviour — the answers reflect reality for each person.

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Different SharePoint and OneDrive permissions

A document visible to a project manager may not be visible to a team member not added to that SharePoint site. Copilot returns what each user can see. Two people asking "what does the project charter say" get different answers if only one of them has access to the charter.

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Different recency windows

Copilot prioritises recent content. If User A received a relevant email yesterday and User B received one three months ago, the same prompt surfaces different content — not because the data is missing, but because recency scoring ranks it differently. The hard email cap of 10 results per query amplifies this effect.

Why Copilot ignored that message

Six specific reasons — with what to do about each

Most common

You are using standalone Copilot Chat on the free tier

Standalone Copilot Chat (at m365.cloud.microsoft or in Office apps) accesses web data only on the free tier. It cannot see Teams messages, SharePoint, or OneDrive. Exception: Copilot Chat within Outlook provides inbox and calendar grounding for all M365 users, even without the paid add-on — but only when accessed inside Outlook itself.

What to do

For email queries, open Copilot Chat inside Outlook — it has inbox access without the paid add-on. For Teams, SharePoint, and cross-app queries, the paid M365 Copilot add-on is required.

Hard limit

The email cap returned other messages first

Copilot returns a maximum of 10 emails per query, ranked by relevance and recency. If your query matches 50 emails, 40 are silently dropped. An important but older message may never appear — not because Copilot cannot access it, but because it ranked below the cut-off. This limit is not displayed in the interface.

What to do

Narrow the prompt: add a specific sender, date range, or subject keyword to push the relevant email into the top 10. "Emails from [name] in March about [topic]" outperforms a broad summary request.

Common

The Teams message is older than 30 days

When using Copilot inside Teams, the default search window for chat messages is the last 30 days of the current thread. Messages outside that window, or from other chats and channels, are not searched unless you specify a date range explicitly in the prompt.

What to do

Include the date range in the prompt: "from December 2025" or "in Q4 last year." Copilot can search further back when instructed explicitly.

Common

You are not a member of that Teams channel

Copilot only accesses Teams channels and group chats you are a member of. A message posted in a project channel you were not added to is invisible — even if colleagues tell you it exists. Private channel messages are also restricted to members of that private channel.

What to do

Ask a channel member to forward the message or share the file directly with you. Once it is in your scope, Copilot can reference it.

Frequent in large teams

The file is on SharePoint but you lack access

An email may reference a SharePoint document, but if you were not granted access to that document or site, Copilot cannot retrieve its content. The email itself may appear in results, but the document it references remains inaccessible. Copilot cannot escalate permissions or prompt you to request access.

What to do

Request SharePoint access through the site owner. Once granted, Copilot will include the document in future queries. No re-indexing required — access is checked at query time.

Less common

The content has a sensitivity label that restricts extraction

Files and emails classified with Purview sensitivity labels may have usage rights that block content extraction. Copilot respects these rights — it will not surface the content of a document marked "Confidential — No Copy" even if you can open it in Word. The file exists in your scope; the content does not reach the model.

What to do

Check the sensitivity label on the document. If the label is the constraint, contact your Information Protection admin — the label configuration, not Copilot, is the control point.

Common false assumptions

Assumption

The Copilot Chat included in my M365 E3 or E5 licence searches my work emails and Teams messages.

Reality

Partially. Standalone Copilot Chat (free tier) is web-only — no Teams, SharePoint, or OneDrive access. However, as of early 2026, Copilot Chat within Outlook provides inbox and calendar grounding for all M365 users without the paid add-on. The paid add-on is still required for Teams data, SharePoint, and the full Copilot feature set.

Assumption

Copilot searches my entire email history. If I ask about a project from two years ago, it will find the relevant emails.

Reality

Copilot returns at most 10 email results per query, ranked by recency and relevance. Older emails may rank below the cut-off. Narrow the query with a sender name, date, or subject keyword to improve retrieval.

Assumption

Copilot in Teams searches all my Teams conversations — channels, group chats, and direct messages.

Reality

Within the Teams app, Copilot searches the current chat thread only, defaulting to the last 30 days. To search across channels and messages, use Copilot Chat at m365.cloud.microsoft/chat with the Work mode active.

Assumption

My prompts and Copilot's responses are used to train Microsoft's AI models.

Reality

No. Microsoft explicitly states that prompts and responses from M365 Copilot are not used to train foundation models, including Microsoft's own. Your organisational data does not leave your M365 tenant to train AI.

Assumption

Copilot can access any SharePoint content in my organisation — including sites I have not visited.

Reality

Copilot accesses only what your permissions allow. If you do not have access to a SharePoint site, Copilot cannot retrieve content from it. Overshared sites are the exception — if a site grants everyone access, all users can retrieve its content via Copilot.