Use Microsoft Copilot to Catch Up on Long Email and Teams Threads

What This Does

Microsoft 365 Copilot reads a long email chain or Teams channel thread and gives you a structured summary of what was decided, what is still open, and who owes what — so you can catch up on a 40-message thread in 30 seconds instead of reading every reply.

Before You Start

• Your organization has Microsoft 365 Copilot licenses (M365 E3/E5 + Copilot add-on, or M365 Copilot subscription)
• You are using Outlook (web or desktop app) or Microsoft Teams
• The email thread or Teams thread you want to summarize is at least a few exchanges long

Steps

Summarize an Outlook email thread

Open the email thread in Outlook. At the top of the message pane, you will see a Summary by Copilot banner that appears automatically on longer threads — click Show summary to expand it. If the banner is not visible, open the Copilot pane by clicking the Copilot icon (sparkle) in the top-right toolbar, and type: "Summarize this thread."

Copilot generates a 3–5 bullet summary: key decisions made, open questions, and any commitments or deadlines mentioned. Click through the source citations (highlighted in the summary) to jump to the exact message where each point was made.

Summarize a Teams channel thread

In Microsoft Teams, open a channel and find a thread you need to catch up on. Expand the thread to see all replies. At the bottom of the thread, click the Copilot button (if visible) or select More options (...) on the thread and choose Summarize thread. Note: the thread needs to have at least 1,000 characters of content for the summarize option to appear.

Copilot generates a summary panel on the right side of your screen showing the key points discussed.

Ask follow-up questions

After the initial summary, you can ask Copilot follow-up questions in the chat panel: "What was the final decision on the go-live date?" or "List all action items mentioned in this thread." Copilot answers from the thread content only, so the answers are grounded in what was actually written.

Real Example

Scenario: You were in back-to-back client calls all Thursday afternoon and came back to 47 new messages in a Teams channel about a change request your team has been debating. You need to understand the current status before a 9 AM call the next morning.

What you do: Open the channel thread. Click More options (...) on the top message and select Summarize thread. Then ask Copilot: "What was the final decision on the CR? Who still needs to approve it? Are there any blockers mentioned?"

What you get: A summary telling you that the team agreed on the revised scope (adding mobile notifications), that it still needs sign-off from the client's VP of Technology (mentioned in a message at 4:47 PM), and that the development lead flagged a dependency on the API team that needs to be resolved before work can start. You walk into your 9 AM call fully briefed.

Tips

• In Outlook, Copilot also drafts replies: after reviewing the summary, click Draft a reply and describe what you want to say — Copilot writes the email and you edit before sending.
• Use Teams Copilot during live meetings too: in any Teams meeting, Copilot can answer "What did we decide about X?" in real time while the meeting is still happening.
• If your org uses SharePoint or OneDrive, Copilot in Microsoft 365 Chat (the standalone chat interface) can summarize documents you link to: "Summarize the project charter in [paste SharePoint link]."
• For Outlook threads involving sensitive client information, Copilot processes data within your organization's Microsoft 365 tenant — it does not send data to external servers — but always follow your firm's data handling policy before using AI on confidential client communications.

Tool interfaces change — if a button has moved, look for the Copilot sparkle icon in the top toolbar of Outlook or the thread options menu in Teams.