Microsoft 365 Copilot: Implicit Grounding in Outlook Chat

With implicit Outlook context in Microsoft 365 Copilot Chat, an open email, an email thread, or a highlighted passage becomes the working context for your question directly. Instead of copying content across first, you simply open the message and ask the side chat for a summary, a next step, or a suggested reply. It’s particularly useful for full inboxes — and for those situations where you only have a few minutes between two meetings. Here’s a summary of how the feature works, what’s confirmed, and what to keep in mind when getting started.

 

Info Value: Context without copying
UseCase Use Case: Working through emails
Zeit Read time:
4 minutes
Schwierigkeit Difficulty: Beginner

Implicit Outlook context isn’t a separate app — it’s a way of working with Microsoft 365 Copilot Chat inside Outlook, where the chat can use the email you currently have open as its point of reference. One important point for context: according to Microsoft, grounding on the open email works even without a Microsoft 365 Copilot licence. You only need a licence for the broader work-data grounding — that is, when Copilot needs to reach beyond the open message to your other emails, files, chats, meetings, and the broader organisational graph.

  1. In the new Outlook for Windows or Outlook on the web, open the email you have a question about, so that it’s shown in the reading pane.
  2. Select the Copilot button in the bottom right of the app or via the ribbon, to open the side chat pane. The open email is picked up automatically as context — you’ll see this confirmed by the subject line appearing as a context chip in the prompt field.
  3. Type a question about the open email into the chat field — for example, “Summarise this email” or “What should I reply next?”

Optional: Before asking, highlight a passage of the email to narrow the context to that specific selection (documented by Microsoft; availability depends on rollout — see Things to Keep in Mind).

  • Set the context deliberately: Make sure you have the right email open first. Implicit Outlook context only helps when the right content is in focus.
  • Check the response: For suggested replies in particular, read back over names, commitments, deadlines, and tone. Treat Copilot as drafting support here, not as final sign-off.
  • Mind your work data: Grounding on the open email is available even without a Microsoft 365 Copilot licence. The full feature set — grounding beyond the single message across emails, files, chats, and meetings — requires the paid Microsoft 365 Copilot subscription.
  • Be careful with sensitive emails: As soon as you open Copilot Chat alongside an open email, its content is automatically passed as context — even when you actually want to ask about something else entirely. If the open message contains confidential information (HR, legal, or customer matters, for instance), check beforehand whether your company’s policies permit processing that content in Copilot at all.

Room for improvement:

  • Highlighting to narrow context: According to Microsoft, selecting a passage in the open email should restrict the context to exactly that selection. In our testing, we couldn’t reproduce this step — automatic grounding on the open email worked, but narrowing via highlighting didn’t. Since the feature is clearly rolling out in stages, it may not yet be available in every build or tenant.
  • Close the email for unrelated questions: If you want to ask Copilot something that has nothing to do with the open message, close it first or start the chat from the inbox list, or remove the reference to the email manually. That way the content of the open email isn’t passed as context unintentionally — particularly relevant for confidential messages.
  • Glance at the context chip: Before prompting, check the subject line in the prompt field to confirm Copilot is actually referring to the email you mean — before you rely on the answer.

Implicit Outlook context in Microsoft 365 Copilot Chat is a small but genuinely practical improvement: open an email, ask in the chat, and get an answer in the right context. The real win is the prep work that disappears — no copying, no long context block, no detour through a separate reference. For anyone with a full inbox, that can take noticeable pressure off the first pass through their mail.

If you want to try it, test the new part specifically: leave an email open, open Copilot Chat, and ask a question about the message without adding any further detail — if the subject line appears as context in the prompt field, implicit grounding is working. The rest of the feature set — summarising, drafting replies — you’ll already know from Outlook; what’s new here is mainly that the general chat establishes the connection on its own.