Use Outlook Copilot to Summarize Long Supplier Email Threads

What This Does

Copilot in Outlook reads a long email thread and gives you a 3–5 sentence summary of what was discussed, what decisions were made, and what action items remain — so you can catch up on a supplier escalation thread in 30 seconds instead of reading 25 emails.

Before You Start

• You have Outlook open (desktop app or web at outlook.com / outlook.office.com)
• Microsoft 365 with Copilot enabled (M365 Business Standard + Copilot or equivalent)
• An email thread you want to summarize is open

Steps

1. Open the email thread you want to summarize

Find a long supplier email thread in your inbox — a PO status chain, a shortage escalation, or a pricing discussion. Click on it to open the thread.

2. Find the Copilot summary

At the top of the email thread (above the first message), look for a Copilot banner or a "Summarize" button. In the desktop app, it may appear as a small bar at the top of the reading pane. In Outlook Web, it appears as a Copilot icon near the thread header.

Click Summarize or Copilot summary.

3. Read the generated summary

Copilot generates a brief summary covering:

• What the thread is about
• Key decisions or commitments made
• Any open action items or unanswered questions
• Who is responsible for what (if stated in the thread)

4. Use the sidebar for follow-up

After reading the summary, you can ask Copilot follow-up questions in the sidebar:

• "What did Supplier X agree to deliver and by when?"
• "What are the open action items in this thread?"
• "Draft a follow-up email asking for a status update on the agreed delivery date"

Real Example

Scenario: You've been out of the office for a day, and there's a 22-email thread about a shortage from your packaging supplier. You need to know the current status before your 2pm call.

What you do: Open the thread, click Summarize. Copilot returns: "Supplier confirmed a 3-week delay on PO #48291 due to a raw material shortage. Your team requested an expedited partial shipment; supplier agreed to ship 40% of the order by 3/28. Logistics is arranging a spot truck. Outstanding: supplier needs delivery address confirmation by EOD today."

What you get: 30-second catch-up vs. 15–20 minutes of reading — exactly the information you need before the call.

Tips

• Copilot summarization works best on threads with 5+ emails. For short threads, just read them.
• For threads where you need to document the agreed resolution for your records, ask: "Write a 2-sentence summary of the resolution reached in this thread" and paste it into your PO tracking notes.
• If Copilot isn't available in your Outlook, use ChatGPT instead: copy the key emails from the thread and paste them with "Summarize this supplier email thread — what was agreed and what actions are pending?"

Tool interfaces change — if the Copilot button has moved, look for similar AI/sparkle options in the thread header or the three-dot menu.