Outlook cannot connect to M365 on RDSH with FSLogix

Question

Hi,

I have deployed RDSH on Windows Server 2022.

A user is having problems configuring Outlook to Exchange Online.

When I try to configure Outlook, I get an autodiscover error:

Your connection is not secure.

Another user on RDSH doesn't have any problems configuring Outlook and it works.

I have tried to delete Outlook items for AppData and Registry for this user.

Where can I find a reason for this?

Answer 1

Hi,@drClays

Thanks for posting your question in the Microsoft Q&A forum.

Based on the screenshot you provided, it's clear that you're having problems with your certificate.

Here are my suggestions:

1.Examine the certificate details:   

• When the error appears in Outlook, click on “View Certificate” if possible. Look at the certificate’s subject name(s) and chain. (Often, if the autodiscover request is being redirected to your RDSH’s own certificate rather than the expected certificate for Exchange Online, you can get such a warning.)   
• Make sure that no group policy or configuration on the RDSH is forcing a particular autodiscover URL or intercepting the connection.

2.You can use Test Email Autoconfiguration to check the specific situation first. The specific steps are as follows:

• Start Outlook.
• Press and hold the Ctrl key, right-click the Outlook icon in the notification area, and then click Test E-mail AutoConfiguration.
• Verify that the correct email address is in the E-mail Address box.
• In the Test E-mail AutoConfiguration window, click to clear the Use Guessmart check box and the Secure Guessmart Authenticaton check box.
• Click to select the Use AutoDiscover check box, and then click Test

3.Test connectivity:

Use Microsoft Remote Connectivity Analyzer to test connectivity and diagnose issues: Microsoft Remote Connectivity Analyzer.

You can refer to this link:https://learn.microsoft.com/en-us/outlook/troubleshoot/connectivity/error-when-outlook-uses-rpc-https-connect-server?source=recommendations

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.