Prompting Guide
How to Prompt Copilot to Triage Your Inbox
Not every unread message deserves the same attention.
Microsoft 365 Copilot can look at a pile of email subject lines and first lines and tell you, in order, which ones need a reply today, which can wait, and which don't need anything from you at all. What it can't do is read your actual inbox on its own: you have to paste the material in, or point it at a thread already open in Outlook, and the prompt you use decides whether the sort it gives back is actually useful or just a reshuffled version of the same overwhelming pile.
Microsoft 365 Copilot triages your inbox better when you paste in the subject lines and opening lines of your unread messages and ask it to sort them into groups like Reply Today, Can Wait, and No Action Needed, with one line explaining why each one landed where it did. For any single long thread in Outlook, you can also select Summary by Copilot at the top of the thread first, then use that summary to decide whether it needs a reply today.
Published
Try it with your own inboxPaste in your unread subject lines and get a sorted list back in seconds, free, no account needed.Try it freeKey Takeaways
- Paste in subject lines and opening lines at minimum; full message text if the sender or subject alone doesn't make the urgency clear.
- Tell Copilot what counts as urgent for you specifically. "Anything from my manager or a client" is a rule it can apply; "important stuff" is not.
- For a single long thread, select Summary by Copilot at the top of it in Outlook first, then decide from the summary whether it needs attention today.
- Ask for a one-line reason next to each sorted email, not just the sort itself, so you can sanity check the triage instead of trusting it blindly.
- Spot-check the Reply Today group against your own instinct before you start working through it.
Copy and Paste
Prompts You Can Use Today
Sorting a full inbox into three groups
Here are the subject lines and first lines of everything unread in my inbox: [paste the list]. Sort them into three groups: Reply Today, Can Wait Until Later This Week, and No Action Needed. For each email, give a one-line reason for where you put it. Treat anything from my manager, [names of key people], or a client with a stated deadline as automatically Reply Today.
Replace the bracketed names with the specific people whose messages you always want flagged as urgent.
Finding the one email that actually needs you today
Out of these unread emails, which single one is most likely to cause a real problem if I don't respond today: [paste the list]. Explain your reasoning in a sentence or two. Don't sort the rest; just tell me the one that matters most right now.
Useful when you have only a short window before a meeting and need the single highest-priority item, not a full sort.
Deciding whether a long thread needs a reply today
I just ran a thread summary with Summary by Copilot on this email: [paste the summary, or describe it]. Based on that summary, does this need a reply today, or can it wait? Tell me why in one sentence, and flag anything in the summary that seems time-sensitive.
Run this after summarizing a long thread in Outlook, instead of rereading the whole thing to decide how urgent it is.
Triaging with your own definition of urgent
Sort these emails by urgency, but use my definition of urgent, not a general one: anything involving money, anything from a client, and anything where someone is waiting on me to unblock their work. Everything else, including internal notices and newsletters, goes in a low-priority group: [paste the list].
Good for inboxes where the default sense of 'urgent' doesn't match what actually matters in your specific role.
Clearing out everything that needs no action at all
Of these unread emails, which ones can I archive right now with no risk because they need no reply and no decision from me, like automated notices or threads that already resolved: [paste the list]. List only those, with a one-line reason for each, so I can check before I archive.
A narrower, lower-risk pass than a full triage: it only picks out the emails that are safe to clear, nothing else.
The Structure
The four parts of a prompt that actually triages, instead of just re-listing
Inbox triage follows the same pattern as any other prompt: context, task, format, and a check before you trust the sort.
Context: what counts as urgent for you
Copilot has no idea who your manager is or which client relationships carry weight unless you say so. Name the senders, roles, or situations that should always count as urgent, and treat everything else as negotiable.
Task: sort and prioritize, not draft replies
Triage and reply-drafting are two different jobs. Ask for one at a time. Mixing them risks a reply slipping out that you didn't carefully review, because it rode along with a sort you trusted more.
Format: named groups with a reason attached
Ask for groups like Reply Today, Can Wait, and No Action Needed, and a one-line reason for each email's placement. The reason is what makes the sort checkable instead of a black box you either trust completely or ignore.
Checking: spot-check before you act on it
Before working through the Reply Today list, scan it against your own instinct for anything that looks off. A triage you don't check at all defeats the point of triage, which is to focus your attention, not redirect it somewhere wrong.
Before And After
What changes when you define urgency yourself
The prompt most people start with is "sort my inbox by priority," with a list of emails pasted below. Copilot will make a reasonable attempt using general signals, like whether an email mentions a deadline or comes from outside the company, but general signals miss anything specific to your actual job: the client who always needs a same-day reply even when their emails sound casual, or the internal mailing list that looks urgent but never actually is.
The same request, rewritten: "Sort these emails into Reply Today, Can Wait, and No Action Needed, with a one-line reason for each. Treat anything from my manager, [specific names], or a client with a stated deadline as automatically Reply Today." The content being sorted hasn't changed, but the rule Copilot is applying now matches your actual priorities instead of a generic guess at what priorities might look like.
The one-line reason attached to each email is doing more work than it looks like. Without it, a triage result is just a reordered list you either trust or don't. With it, you can scan the reasons in a few seconds and catch the one email that got filed as low-priority for a reason that doesn't actually apply to your situation, before you act on a sort that's wrong in one specific spot.
Common Mistakes
What makes an inbox triage less useful than it should be
These are the gaps that turn a triage pass into one more thing to double-check from scratch.
Not defining urgency for your specific job
A generic sense of "important" misses the client who sounds casual but needs a same-day answer, and flags the internal thread that looks formal but genuinely isn't urgent. Say what urgent means for you, specifically.
Asking for sorting and replies in one step
A combined prompt can produce a drafted reply to an email that actually needed more thought than a quick triage pass gives it. Keep sorting and drafting as separate requests so each gets the attention it needs.
Skipping the reason for each placement
A sort with no explanation is a black box: useful only if you're willing to trust it completely. A one-line reason per email turns the same sort into something you can actually verify in a few seconds.
Trusting the sort without a spot check
A triage pass is a strong starting point, not a guarantee. Scan the Reply Today group against your own sense of the day before diving in, since the cost of missing something genuinely urgent is higher than the cost of a quick check.
Sourced From Microsoft
Deciding fast on a single long thread
A full inbox triage works on subject lines, but one long thread buried in the middle of it needs a different move: open the thread and select Summary by Copilot (or it might say Summarize) at the top of it. The summary appears at the top of the email and may include numbered citations that, when selected, take you to the corresponding message in the thread, which is enough to decide whether the thread needs a reply today without reading all of it first.
If the thread has attachments, like a PDF or a document, those get summarized separately with Summarize a file in new Outlook, worth running if a decision in the thread hinges on something inside the attachment rather than the messages around it. On Outlook for iOS and Android, the same thread summary lives behind the Copilot icon in the toolbar, which matters if you're triaging from your phone between meetings rather than sitting at a desk.
Feed that summary straight into your triage prompt the same way you'd feed in a subject line and an opening line: ask Copilot whether, based on the summary, the thread belongs in Reply Today or can wait, and to flag anything in it that looks time-sensitive.
Before You Act On It
What to check before you work through the sorted list
Scan the Reply Today group first, against your own sense of what's actually pressing today. If something you know is urgent landed in Can Wait, or vice versa, that's worth correcting before you start working through the list, not after you've already spent your morning on the wrong priorities.
Read the one-line reason attached to anything that surprises you. A reason that says "no deadline mentioned" for an email you know is time-sensitive tells you exactly where the sort went wrong: it had no way to know about a deadline that exists outside the email itself, like a verbal commitment made in a meeting.
If you're going to archive anything Copilot flagged as No Action Needed, do a final skim of the subject lines first. A triage pass works from the text it was given; it has no way to catch an email that needs action for a reason that isn't visible in the subject or opening line alone.
When This Isn't The Right Tool
When to triage the inbox yourself instead
An inbox with genuinely sensitive material, like a legal matter, a personnel issue, or anything you wouldn't want summarized and sorted by a general-purpose assistant even in principle, is worth triaging yourself rather than pasting into a prompt at all, regardless of how convenient the shortcut would be.
On a day with very few unread messages, a triage prompt is often more overhead than it's worth. The tool earns its place on the day your inbox is overwhelming and your time before the next meeting is short, not on a quiet day with only a handful of emails you can read yourself in less time than it would take to write the prompt.
Triaging one inbox is the easy part
The harder skill is writing urgency rules that actually match your job, and knowing when a quick sort isn't the right tool at all. Nightschool AI's Copilot first week at work course walks through real inbox, document, and meeting scenarios in Outlook, Word, Excel, and Teams.
Frequently Asked Questions
What should I paste into the prompt when asking Copilot to triage my inbox?
Subject lines and opening lines at minimum, or full message text when the sender and subject alone don't make the urgency clear. For one long thread, a Summary by Copilot result works as well as raw text.
How do I make sure Copilot's sense of 'urgent' matches mine?
Spell it out explicitly: name the people, roles, or situations that should always count as urgent for you, rather than relying on a general sense of importance that may not match your specific job.
How do I decide fast whether one long thread needs a reply today?
Select Summary by Copilot at the top of the thread in Outlook, then ask whether, based on that summary, it belongs in Reply Today or can wait. The summary's citations let you check the specific message a point came from before you decide.
Should Copilot draft replies during the same triage pass?
Keep sorting and reply-drafting as separate steps. Combining them risks a reply slipping through without the review it needed, because it was generated alongside a sort you trusted more readily.
Why should each sorted email have a reason attached?
A reason turns the sort into something you can check in seconds. Without one, you're left either trusting the whole triage blindly or re-reading every email yourself, which defeats the purpose of triage.
Is it safe to archive emails Copilot sorts as No Action Needed?
Do a final skim of the subject lines first. The sort works from the text it was given, and it has no way to catch an email that needs action for a reason not visible in the subject or opening line, like a verbal commitment made elsewhere.
Can Copilot triage a genuinely sensitive inbox, like one with legal or HR material?
That's worth handling yourself rather than pasting into any prompt, regardless of convenience. Reserve prompted triage for routine work email, not material you wouldn't want summarized by a general-purpose assistant.
How often should I spot-check a triage sort before trusting it?
Every time, at least briefly. Scan the Reply Today group against your own instinct before working through it, since the cost of missing a genuinely urgent email outweighs the cost of a short check.
A clear inbox doesn't take long with the right prompt
The sort is reusable every day. Defining what counts as urgent for you is the part worth getting right once.