Use Microsoft 365 Copilot in Outlook to Summarize Long Threads and Draft a Reply

What This Does

A few days out of the office, or one busy week, and a thread with a funder or a board member has grown to twenty messages you have to catch up on before you can reply intelligently. Copilot in Outlook reads the whole thread and produces a short summary at the top, then drafts a reply covering the open questions, so catching up takes minutes instead of scrolling through every message.

Before You Start

• Your organization has the Microsoft 365 Copilot add-on license on top of a base Microsoft 365 Outlook subscription. Summarize and Draft are add-on features, not something every Microsoft 365 plan includes by default, so confirm with your Microsoft 365 administrator if you don't see the options described below
• Nonprofits may qualify for a discount on the Copilot add-on. Check Microsoft's current nonprofit pricing page rather than assuming the cost
• You're using new Outlook, Outlook on the web, Outlook for Mac, or the mobile app. Legacy Outlook for Mac doesn't support these features

Steps

1. Find the AI feature

Open the long thread and look near the top of the message for Summary by Copilot (it may just say Summarize). On Mac, the same control appears inside a Summary by Copilot box at the top of the thread. On mobile, tap the Copilot icon in the toolbar instead.

2. Tell it what you need

Select Summarize and Copilot scans the whole conversation for key points, producing a short summary at the top of the thread, often with numbered citations that jump to the specific message each point came from. If the thread includes an attached PDF, Word, or PowerPoint file, look for a Summarize a file option to get a separate summary of the attachment itself.

3. Review and use the result

Read the summary against your own sense of the thread, especially anything the funder or board member asked directly, since a missed question in your reply looks worse than a slow one. To draft a reply, click Help me reply in the message area, which opens Copilot Chat so you can describe what you want the reply to cover. Review the draft, fill in any specifics Copilot left generic, and send.

Real Example

Scenario: A funder thread about a grant renewal has grown to fifteen messages over two weeks while you were focused on an audit, and the funder's last message asked for updated outcomes data and a decision on the renewal timeline.

What you type/do: Select Summarize on the thread, and then click Help me reply and type: "Draft a reply confirming we can share updated outcomes data by next Friday and that we'd like to schedule the renewal call for the week after."

What you get: A summary flagging the funder's two open questions, plus a reply draft that addresses both, ready to review for tone and send.

Tips

• Check the citations in the summary before you act on it. If a numbered link points to the wrong message, the summary may have attributed a point to the wrong person in the thread.
• Use Help me reply for the first pass on a reply you'd otherwise spend real time drafting, and then edit in your own voice before sending. A funder can tell when a reply reads like a form letter.
• For a thread that includes a sensitive attachment, summarize the thread text but skip the Summarize a file option on anything you wouldn't otherwise forward to a third party.

Funder and donor correspondence can reference gift amounts, program details not yet public, or a board decision still in progress. Before you lean on a Copilot-drafted reply for a sensitive thread, confirm your organization's Microsoft 365 Copilot license and data settings match what you'd be comfortable having processed by the feature, and check with your board chair before committing to anything not yet approved.

Tool interfaces change. If a button has moved, look for similar AI/magic/smart options in the same menu area.