Microsoft 365 Copilot Draft Reply Button Greyed Out in Outlook: Fix

You open an email in Outlook for Windows or Outlook on the web, click the Copilot icon, and the Draft Reply button appears but is greyed out and unclickable. This problem typically occurs because the active email account does not have a valid Copilot license assigned, the Outlook client version lacks the required Copilot integration update, or the email message format is read-only or protected. This article explains the three root causes that disable the Draft Reply button and provides step-by-step fixes for each scenario so you can resume drafting replies with Copilot.

Why the Copilot Draft Reply Button Is Greyed Out in Outlook

The Draft Reply button in Copilot becomes greyed out when Outlook cannot verify that the current conversation or account meets the requirements for Copilot to generate a reply. The technical root cause falls into one of three categories.

Missing or Invalid Copilot License

Copilot for Microsoft 365 requires a paid license assigned to the user account in the Microsoft 365 admin center. If the license is missing, expired, or assigned to a different tenant, Outlook blocks the Draft Reply button. The button remains visible but greyed out because the Copilot service endpoint returns a 403 Forbidden response when Outlook queries the user’s entitlement.

Outdated Outlook Client Version

The Draft Reply feature requires Outlook version 2402 (Build 17328.20000) or later for Windows, or the latest Outlook on the web build. Older builds lack the CopilotReply API endpoint that enables the Draft Reply button. Outlook shows the button but cannot activate it because the underlying code path is missing.

Protected Email or Read-Only Message Format

Copilot cannot draft a reply to emails that are encrypted with Microsoft Purview Message Encryption, protected by Information Rights Management, or formatted as TNEF (Transport Neutral Encapsulation Format) such as signed messages. Outlook detects the protection header and disables the Draft Reply button to prevent Copilot from accessing content it cannot legally process.

Steps to Re-enable the Copilot Draft Reply Button

Follow the steps below in the order listed. Each step addresses one of the root causes. Test the Draft Reply button after each step before moving to the next.

Step 1: Verify the Copilot License Assignment

1. Open the Microsoft 365 admin center
   Go to admin.microsoft.com and sign in with a Global Admin or Billing Admin account.
2. Navigate to Billing > Licenses
   Select Billing in the left navigation, then click Licenses.
3. Select Copilot for Microsoft 365
   Click the Copilot for Microsoft 365 product row to view assigned users.
4. Locate the affected user
   Search for the user who sees the greyed-out button. Check the Assigned column. If it shows Not assigned, click the user name, select Edit product licenses, enable the Copilot license, and click Save.
5. Wait for propagation
   License changes can take up to 30 minutes to propagate to Outlook. Close and reopen Outlook after the wait period.

Step 2: Update Outlook to the Latest Build

1. Open Outlook and go to File > Office Account
   In Outlook for Windows, click File, then Office Account.
2. Check the version number
   Under Product Information, locate the version string. It should be Version 2402 (Build 17328.20000) or later. If the version is older, continue to the next sub-step.
3. Click Update Options > Update Now
   Select Update Options and then Update Now. Outlook will download and install the latest update. Restart Outlook when prompted.
4. Verify the update succeeded
   After restart, go back to File > Office Account and confirm the version is now 2402 or later.

Step 3: Check the Email for Protection or Format Restrictions

1. Identify protected messages
   Look for a lock icon, a banner that says Encrypted or Do Not Forward, or a digital signature indicator in the email header. These messages block Draft Reply.
2. Switch to a non-protected email
   Select a different email in your inbox that does not have encryption or IRM protection. The Draft Reply button should become active.
3. Use Outlook on the web as a fallback
   If the email is protected and you must reply, open outlook.office.com in a browser. Some protection policies allow Draft Reply on the web even when the desktop client blocks it. If the button is still greyed out, the policy explicitly denies Copilot access to protected content.

If Copilot Still Has Issues After the Main Fix

If the Draft Reply button remains greyed out after completing all three steps, one of the following edge cases may apply.

Copilot Draft Reply Button Works in One Account but Not Another

Outlook supports multiple email accounts. The Draft Reply button only works for the account that has the Copilot license. If you have a personal Outlook.com account and a work account, switch the active account by clicking the account avatar in the top-right corner of Outlook. Select the work account. If the work account still shows a greyed-out button, repeat Step 1 for that specific account.

Copilot Draft Reply Button Disappears Entirely After an Update

Some Microsoft 365 updates reset the Copilot add-in state. Go to Outlook > Get Add-ins and search for Copilot. If the add-in shows as Disabled, click the three dots next to it and select Enable. Restart Outlook. The Draft Reply button will reappear and become active.

Copilot Draft Reply Button Is Greyed Out for All Emails Including Plain Text

This indicates a tenant-level policy is blocking Copilot. Contact your Microsoft 365 administrator. Ask them to check the Microsoft 365 admin center > Settings > Org settings > Copilot page. Ensure the toggle Allow Copilot to access Microsoft Graph data is turned on. Also confirm that no conditional access policy in Microsoft Entra ID blocks the Copilot service endpoint copilot.microsoft.com and all subdomains.

Copilot Draft Reply vs Manual Reply: Key Differences

Item	Copilot Draft Reply	Manual Reply
Trigger	Click Copilot icon then Draft Reply button	Click Reply or Reply All button
Content generation	AI generates a draft based on the email thread	User types the response manually
License required	Copilot for Microsoft 365 license assigned	No extra license beyond Exchange Online
Protected email support	Not supported for encrypted or IRM-protected messages	Supported for all message types
Outlook version requirement	Version 2402 Build 17328.20000 or later	Any supported Outlook version

The Draft Reply button is a time-saver for routine responses, but it requires specific conditions that manual replies do not. Understanding these differences helps you decide when to use Copilot and when to type manually.

You can now identify why the Copilot Draft Reply button is greyed out and apply the correct fix. Start by verifying the license assignment in the Microsoft 365 admin center, then update Outlook to the latest build. If the problem persists, check the email for encryption or protection policies. As an advanced tip, create a shared mailbox with a Copilot license and assign delegates. The Draft Reply button works for shared mailboxes as long as the delegate’s account has the license and the mailbox is added in Outlook with Send-As permissions.