outlook just disconnect randomly

Hello, my name is Mario, and I would be happy to assist you with your issue.

I’m sorry for what happened!

I believe you might be experiencing this issue due to an IP/DNS change, so I would like to ask you:

Do you have a DNS configuration set on your network adapter?

Do you connect to the internet through a VPN?

Is the connection made through a network or directly via a router (Wi-Fi or cable)?

Best regards,

Mario B.

Hi @y stoneyy,

Welcome to Microsoft Q&A.

Thank you for providing such a precise and technical description of your issue. You have correctly diagnosed a very specific and difficult problem related to how the Windows client handles certificate trust and session renewal after a network state transition.

The behavior you're describing is not a general connectivity issue but rather a failure in the client's ability to re-establish a secure TLS session with the Exchange server's certificate. This can happen if the operating system's SSL cache retains stale information or if the certificate's trust path is not fully established for all network conditions.

Here is the most likely cause and the steps you can take to resolve it:

Step 1: Clear the SSL State

The first and most effective step is to clear the SSL cache in Windows. This will force your system to re-download and re-evaluate the certificate from your Exchange server upon the next connection.

1. Open the Control Panel (you can search for it in the Start Menu).
2. Go to Network and Internet > Internet Options.
3. In the new window that appears, click on the Content tab.
4. Click the Clear SSL State button.

Step 2: Manually Import the Certificate

To ensure your PC fully trusts the server's certificate under all conditions, you can manually import the public certificate and its root authority.

1. Access your Exchange server's certificate from your browser by navigating to the server's URL. Click the padlock icon next to the URL, view the certificate, and export it as a .cer file.
2. Open the Microsoft Management Console (MMC) by typing mmc in the Run dialog.
3. Go to File > Add/Remove Snap-in.
4. Select Certificates and click Add. Choose "Computer account" and then click through the prompts to finish.
5. In the console tree, navigate to Certificates (Local Computer) > Trusted Root Certification Authorities > Certificates.
6. Right-click on Certificates, go to All Tasks > Import..., and import the .cer file you exported earlier.

Restart Outlook after performing these steps. This should prevent the intermittent connection failures you're experiencing by ensuring your PC has a full and trusted copy of the server's certificate.

Please try these solutions in the order provided and let me know if any of them help resolve the issue. If the problem persists after trying all these methods, we can explore further troubleshooting steps.

Warm regards   

Chloe L. | Microsoft Q&A Support Specialist

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