Copilot in Outlook writes drafts, rewrites existing text, and suggests tone changes without leaving your inbox

Microsoft Copilot is built into Outlook on the web and the Windows Outlook app. When you open a new email, you'll see a "Copilot" button in the compose window. Click it to open a side panel where you can ask Copilot to draft an email from scratch, rewrite something you've already started, or adjust the tone of what you've written. Copilot pulls from the context of your email thread, so it understands who you're writing to and what the conversation is about.

The feature works best when you give it specific direction. Instead of asking Copilot to "write an email," tell it what you need: "Draft a professional email asking for a deadline extension" or "Rewrite this to sound less formal." The more detail you provide, the closer the result will be to what you actually want to send.

Key Takeaways

  • Copilot appears as a button in the Outlook compose window on the web and Windows app, not on mobile or Mac versions.
  • You can ask Copilot to draft a new email, rewrite text you've already written, or change the tone of your message.
  • Copilot reads the email thread you're replying to, so it understands context about who you're writing to and what the conversation covers.
  • Always review and edit Copilot's output before sending—it may miss nuance, include details you didn't intend, or misread your relationship with the recipient.

Where to find the Copilot button in Outlook

On Outlook on the web, open a new email or click Reply on an existing message. In the compose window, look for the Copilot icon (it looks like a sparkle or star) in the toolbar at the bottom. On the Windows Outlook app, the button is in the same location. Click it to open the Copilot panel on the right side of your screen.

Copilot is not available in Outlook for Mac or the Outlook mobile app. If you use those versions, you won't see the button. You can still use Copilot on the web version by going to outlook.office.com in your browser instead of opening the desktop app.

How to draft an email from scratch with Copilot

Click the Copilot button and select "Draft with Copilot" or type your request in the text box. Be specific about what you need. For example: "Draft an email to my manager asking to move the project deadline from Friday to next Wednesday. Keep it professional but friendly." Copilot will generate a full email in the compose window, and you can edit it before sending.

If the first draft isn't quite right, you can ask Copilot to try again with different instructions. You might say "Make it shorter" or "Add a specific reason why I need the extension." Each time you submit a new request, Copilot replaces the previous draft.

How to rewrite or adjust tone in an email you've started

If you've already written part of an email and want Copilot to help, type what you have in the compose window, then click Copilot and select "Rewrite." You can ask it to make the email more formal, less formal, more concise, or more detailed. You might say "Make this sound more professional" or "Rewrite this to be friendlier and less blunt."

Copilot will rewrite your entire message based on your instruction. If you only want to change part of it, highlight that section before clicking Copilot, and it will focus on rewriting just that text. Review the result carefully—sometimes rewrites change the meaning or leave out important details you included.

What Copilot can and cannot do in Outlook

Copilot can draft emails, rewrite text, adjust tone, and summarize long email threads. It reads the conversation history so it understands context. It cannot send emails on your behalf, schedule messages, or access your contacts to fill in recipient addresses. You still control when the email goes out and who it goes to.

Copilot also cannot access attachments or files linked in your email. If your message needs to reference a specific document or spreadsheet, you'll need to mention that context in your instructions to Copilot. For example, you might say "Draft an email asking for feedback on the Q4 budget spreadsheet I attached yesterday."

Things to check before sending a Copilot-drafted email

Always read through what Copilot wrote before you send it. Check that the tone matches your relationship with the recipient—Copilot sometimes defaults to formal language even when a casual tone would be better, or vice versa. Make sure all the details are accurate and nothing important is missing. Copilot may invent details or make assumptions about what you want to say.

Pay special attention to the opening and closing. Copilot often uses generic greetings and sign-offs. If you have a specific way you usually start or end emails with this person, edit it to match. Also check that Copilot didn't accidentally include information from a previous email in your thread—it reads context but sometimes pulls in details you didn't intend to repeat.

Privacy and data considerations with Copilot in Outlook

When you use Copilot in Outlook, your email content is sent to Microsoft's servers to generate the response. Microsoft says it does not use your emails to train Copilot or share them with other users, but the text does leave your device temporarily. If your emails contain sensitive information—passwords, financial details, health information, or confidential work data—be aware that you're sending that content to Microsoft's systems.

Your organization may have policies about using Copilot with certain types of information. Check with your IT department or security team if you work for a company with strict data handling rules. For personal emails, the risk is lower, but the principle is the same: Copilot requires sending your text to Microsoft to work.

Frequently Asked Questions

Do I need a paid Microsoft 365 subscription to use Copilot in Outlook?

Copilot in Outlook is included with Microsoft 365 subscriptions. If you use a free Outlook.com account, Copilot may not be available or may have limited features. Check your Outlook settings to see if the Copilot button appears in your compose window.

Can Copilot read emails I've already sent?

No. Copilot only reads the email thread you're currently composing in and the conversation history visible in that thread. It cannot access your sent folder or any other emails in your mailbox.

What if Copilot's draft includes information I didn't ask for?

Delete or edit those details before sending. Copilot sometimes infers context from the email thread and includes details you didn't explicitly request. Always review the full email and remove anything that shouldn't be there.

Can I use Copilot on my phone or tablet?

Copilot is not available in the Outlook mobile app for iPhone, iPad, or Android. You can use it on the web by opening outlook.office.com in your phone's browser, though the experience is smaller and less convenient than on a desktop.

What happens if I ask Copilot to write something inappropriate or unethical?

Copilot has built-in safeguards and will decline requests that ask it to help with harassment, deception, or illegal activity. If you ask it to write something it flags as problematic, it will refuse and explain why. You can still write the email yourself if you choose.