Microsoft Outlook won't open emails

Test the same mailbox in its webmail site first; if messages open there, remove and re-add the account in New Outlook, then repair the app if the error continues.^1^

1. Test whether the account itself works

Sign in through a browser using the account’s email provider:

• Outlook.com, Hotmail, Live, or MSN: use the Microsoft account password belonging to that address. Microsoft documents the browser sign-in process here.^2^
• Gmail, Yahoo, iCloud, or another provider: use that provider’s webmail site and credentials.
• Work or school Microsoft 365 account: use Outlook on the web.

Then try opening several messages.

• If webmail works: the mailbox is accessible, so continue with the New Outlook steps below.
• If webmail also says “Access denied”:
  • For a personal Outlook.com account, use Microsoft’s sign-in assistance. If Microsoft reports that the account is blocked, unblocking requires resetting its password.^3^
  • For a work or school account, contact the organization’s Microsoft 365 administrator. Ask them to check mailbox access, licensing, applicable access policies, and Microsoft 365 service health.
  • For Gmail, Yahoo, iCloud, or another provider, contact that provider’s official support because the denial is occurring outside the Windows Outlook app.

2. Reconnect the account in New Outlook

1. Open New Outlook.
2. Select View → View settings or File → Account info.
3. Open Accounts → Your accounts.
4. Beside the affected account, select Manage → Remove.
5. If it is a non-Microsoft account, choose Remove from this device, not Remove from all devices. Removing it from all devices can remove Microsoft Cloud data across Outlook clients, including items that may not exist in the provider’s webmail.
6. Return to Accounts → Your accounts and select Add Account.
7. Enter the address, complete the provider’s sign-in prompts, and try opening a message again.

Removing the account from Outlook does not delete the email account, but it removes that account’s locally cached content.^4^

For Gmail, Yahoo, iCloud, or some IMAP accounts, complete any provider permission, two-step verification, or app-password prompt displayed during reconnection.^1^

3. Repair or reset New Outlook

If webmail works but reconnecting the account does not:

1. Close Outlook.
2. Open Start → Settings → Apps → Installed apps.
3. Find Outlook (new) and select its More options (…) button.
4. Select Advanced options → Repair.
5. Reopen Outlook and test a message.
6. If the error remains, return to the same page and select Reset, then reopen Outlook and add the account again.

Repair attempts to fix the app without removing its data; Reset returns it to its default state and may remove app data.^5^

The current New Outlook known-issues page does not list this exact “cannot open emails/access denied” combination as a confirmed widespread issue.^6^

If webmail continues to work but reconnecting, Repair, and Reset all fail, use Contact Us on Microsoft’s New Outlook known-issues page or open the Windows Get Help app. Provide the exact error text, the email provider, and confirmation that webmail works—without including the email address, password, or verification codes.

References

1. Outlook access denied, asking for password - Microsoft Q&A
2. How to sign in to Outlook.com | Microsoft Support
3. Unblock my Outlook.com account | Microsoft Support
4. New Outlook
5. Windows 11
6. Fixes or workarounds for recent issues in new Outlook for Windows ...