Outlook connecting to server issue for a single device

Question

I have a laptop that keeps having the 'connecting to outlook server' issue from time to time. Outlook web works during that time. DNS flush doesnt do anything, disabling ipv6 doesnt do anything, exe close and reopen doesnt do anything, killing exe from task manager doesnt do anything, disable/enable of interface doesnt do anything, reconnecting from outlook exe's connection status doesnt do anything. But a complete laptop restart solves the issue. This issue is only happening on a single laptop. It has an ethernet to USB adaptor but changing the adaptor doesnt solve the problem. the same adaptor connected to another laptop doesnt cause this issue. how to solve this?

Answer 1

Hi @Anonymous

Thank you for reaching out to our Q&A forum.

To assist you better, I will need more information.

Do you use any VPN or Antivirus software?

May I know which Outlook version are you using? (You can check this in File > Office account > about Outlook)

In your Classic Outlook, go to Send/Receive tab > click Update Folder. Does it show any error message? If yes, please provide it.

Additionally, here are some steps you can try:

• Open Outlook in safe mode - Microsoft Support (If this works, the problem is likely one of the add-ins, you can go to File > Option > Add-ins > Go > Uncheck any suspicious add-ins)
• Repair an Office application - Microsoft Support (Choose Repair Online)
• Create an Outlook profile - Microsoft Support(This doesn't affect your data)
• Lastly, reinstall Classic Outlook app.

I look forward for your reply.

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Answer 2

The issue you're experiencing with Outlook on a single laptop could be related to several factors, especially since it works fine on other devices with the same adapter. Here are some steps you can take to troubleshoot and potentially resolve the issue:

1. Update Network Drivers: Ensure that the network adapter drivers are up to date. Outdated drivers can cause connectivity issues.
2. Check for Software Updates: Make sure that both Windows and Outlook are updated to the latest versions. Sometimes, bugs in older versions can lead to connectivity problems.
3. Disable Third-Party Add-ins: Third-party add-ins can interfere with Outlook's performance. Start Outlook in safe mode to see if the problem persists. If it works fine in safe mode, consider disabling third-party add-ins:
   • Open Outlook in safe mode by running outlook.exe /safe.
   • Go to File > Options > Add-Ins.
   • In the Manage box, select COM Add-ins and click Go. Uncheck any third-party add-ins and restart Outlook.
4. Network Configuration: Since the issue is specific to one laptop, check the network settings. You might want to reset the network settings or try using a different network configuration.
5. IPv4 Checksum Offload: If the issue persists, consider disabling the IPv4 Checksum Offload feature. This can sometimes resolve connectivity issues:
   • Go to Control Panel > Network Connections.
   • Right-click the network adapter and select Properties > Configure > Advanced tab.
   • Find IPv4 Checksum Offload and set it to Disable.
6. Check for Service Issues: If multiple users in your organization experience similar issues, it could be a service issue with Microsoft 365. Check the Microsoft 365 Service health status.

If none of these solutions work, a complete restart may be necessary, but it would be beneficial to identify the root cause to avoid frequent restarts in the future.

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References:

• Error when Outlook tries to connect to a server by using an RPC connection or an HTTPS connection: There is a problem with the proxy server's security certificate
• Can't sign in or activate Outlook and Microsoft 365 applications
• Fix Outlook connection problems for Microsoft 365 account