Outlook cannot connect to the server

If Classic Outlook shows Working Offline, select Send/Receive → Work Offline once to return it online; if it shows Disconnected or Trying to connect, test webmail next to distinguish a server/account issue from a local Outlook issue.^1^

Since repairing Outlook did not resolve the problem, do not repeat that repair.

1. Check the connection status

Look at the status bar at the bottom of Outlook:

• Working Offline: Select Send/Receive → Work Offline. The button should no longer be shaded, and the status should change to Connected.
• Disconnected or Trying to connect: Open your organization’s webmail in a browser and try sending and receiving a test message.
  • Webmail also fails: This points to an account, server, or Microsoft 365 service problem. Contact your organization’s Microsoft 365/Exchange administrator.
  • Webmail works: The mailbox and server are available; continue with the local Outlook steps below.^1^

If you recently changed your mailbox password, sign in again with the new password when Outlook prompts. A changed password can prevent Classic Outlook from connecting.^2^

2. Create a fresh Outlook profile

When webmail works but Outlook remains disconnected, create a new profile rather than reinstalling Office:

1. Close Outlook.
2. Open Windows Control Panel.
3. Select Mail (Microsoft Outlook).
4. Select Show Profiles → Add.
5. Enter a profile name, such as OutlookNew.
6. Add your business email account and complete authentication.
7. Under Always use this profile, select the new profile.
8. Select Apply, then open Outlook.

A new profile creates fresh account and connection settings without deleting mail stored in the server mailbox. Damaged profiles are a common cause of Outlook connectivity failures.^3^

Do not remove the old profile until the new profile connects and all required mail, calendars, archives, and shared mailboxes are available.

3. If a new profile does not connect

Test Outlook without add-ins:

1. Close Outlook.
2. Press Windows key + R.
3. Enter:

      outlook.exe /safe
   

4. Select OK.

If Outlook connects in Safe Mode, disable add-ins through File → Options → Add-ins → Manage: COM Add-ins → Go, then re-enable them individually to identify the problem add-in.^2^

If it still does not connect, run the Classic Outlook troubleshooter in the Windows Get Help app. These troubleshooters cover Outlook startup and profile-setup problems and apply to Classic Outlook, not new Outlook.^4^

4. Business administrator checks

If multiple employees are affected, the Microsoft 365 administrator should check Microsoft 365 Service health → Exchange Online. An administrator can also run the Outlook User Connectivity diagnostic; this requires an administrator account and is unavailable in certain government and region-specific Microsoft 365 environments.^3^

Record the exact Outlook status and any error code before escalation, because Working Offline, Disconnected, authentication prompts, and numbered send/receive errors require different fixes.

References

1. [Classic Outlook](https://support.microsoft.com/outlook/getstarted/how-to-work-offline-in-outlook-for-windows#status-messages-in-classic-outlook)
2. [New Outlook](https://support.microsoft.com/outlook/i-can-t-send-or-receive-messages-in-outlook#have-you-changed-your-password-recently)
3. Fix Outlook connection problems for Microsoft 365 account
4. Resolve Outlook for Windows issues with automated troubleshooting tools | Microsoft Support