Outlook New and Classic not loading new or sending new mails.

A widespread Microsoft 365/Outlook service disruption was reported on November 12–13, 2026, so check Microsoft service health and webmail before changing either Outlook installation.^1^

1. Determine whether this is the service incident

1. Open your email provider’s webmail in a browser.
2. Send a short test message to yourself.
3. Check whether it arrives.

For an Outlook.com/Hotmail/Live mailbox, also check Microsoft’s Service Health Status page. Microsoft directs Outlook.com users there for current service problems.^2^

• Webmail also cannot send or receive: this is not limited to Outlook for Windows. During an active incident, use the status page for updates and wait for service restoration; reinstalling or resetting Outlook is unlikely to help.
• Webmail works normally: the mailbox is operating, so continue with the local Windows steps below.
• Work or school account: ask the Microsoft 365 administrator to check Microsoft 365 admin center → Health → Service health.

2. Check the shared connection and authentication

Because both New Outlook and Classic Outlook are affected, check conditions common to both:

• Confirm ordinary websites open from the same PC.
• If the email password was changed recently, sign in again in Outlook. In New Outlook, select the account name, choose Continue, and enter the updated password.
• If Outlook asks for an app password, obtain one from the email provider and use it instead of the regular password.
• Check mailbox storage. A full Microsoft cloud mailbox can prevent both sending and receiving.^3^

For a Gmail, Yahoo, iCloud, ISP, POP, or IMAP account, use the provider’s documented server settings rather than substituting Microsoft 365 SMTP settings.

3. Test each Outlook client

New Outlook

1. Select View → Sync.
2. Watch for the synchronization status at the bottom of the message list.
3. Check Outbox. If the oldest message has a large attachment, remove it and try sending a small text-only message.

The manual Sync capability is not identical for third-party accounts such as Gmail, Yahoo, iCloud, POP, and IMAP.^3^

If webmail works but New Outlook still fails:

1. Open Settings → Accounts → Email accounts.
2. Remove the affected account.
3. Close Outlook completely.
4. Reopen it and add the account again.

Removing the account clears its local synchronization state; verify that important mail exists in webmail before doing this.^4^

Classic Outlook

1. Check the bottom status bar for Disconnected, Working Offline, or Trying to connect.
2. If Working Offline appears, select Send/Receive → Work Offline once to return online.
3. Select Send/Receive All Folders and retest.^3^

If it remains disconnected while webmail works, start Classic Outlook without add-ins:

1. Press the Windows key.
2. Enter outlook.exe /safe.
3. Press Enter, then test sending a text-only message.

If Safe Mode works, an add-in is interfering; create a new Outlook profile or disable add-ins selectively. If it does not, use Microsoft’s Classic Outlook troubleshooters. These troubleshooters do not apply to New Outlook.^5^

When requesting further help, provide the account type, whether webmail works, the exact status shown in Classic Outlook, and any error code—without posting the email address or other personal information.

References

1. Widespread Microsoft outage takes down Outlook and other 365 services
2. Fixes or workarounds for recent issues on Outlook.com | Microsoft Support
3. I can't send or receive messages in Outlook | Microsoft Support
4. It appears a new verion of outlook was installed and I cannot now receive email - Microsoft Q&A
5. Issues sending and receiving email | Microsoft Support