Encrypted connection to the server is not available

MAPI is enabled at the organization level. Other employees do not experience any problems.

Other recommendations did not help.

Since MAPI is enabled at the organization level and other employees are not experiencing the issue, it seems likely that the issue is specific to the configuration of the affected user. Here are a few steps you can try:

1. Even if MAPI is enabled at the organization level, it can be disabled for individual mailboxes. Run the following command in the Exchange Management Shell to ensure that MAPI is enabled for a specific user:

Get-CASMailbox -Identity user@domain.com | Format-List MAPIEnabled

If it is disabled, you can enable it with the following command:

Set-CASMailbox -Identity user@domain.com -MAPIEnabled $true

2. Ensure that the MAPI virtual directory is configured correctly. You can check and set the internal and external URLs with the following command:

Get-MapiVirtualDirectory | Format-List InternalUrl,ExternalUrl
Set-MapiVirtualDirectory -Identity "ServerName\mapi (Default Web Site)" -InternalUrl https://mail.domain.com/mapi -ExternalUrl https://mail.domain.com/mapi

I checked it out. It's all set up correctly. MAPI is enabled for the user.

Hi @Андрей Михалевский,

It sounds like you've done a lot of great troubleshooting already, but since MAPI is enabled at the organization level and other employees aren't experiencing the same issue, let's go over some more specific checks and potential fixes:

1. Verify User-Specific MAPI Settings

Even if MAPI is enabled at the organization level, it can still be disabled at the individual user level.

If it's disabled, enable it.

2. Check MAPI Virtual Directory Configuration

Ensure that the MAPI virtual directory is set up correctly on the Exchange server, especially the internal and external URLs.

3. Test Autodiscover Service

The Autodiscover service plays a crucial role in MAPI connectivity. Even if it's not directly the issue, it's still worth verifying. You can test it by:

-Holding the Ctrl key, right-clicking the Outlook icon in the system tray, and selecting Test E-mail AutoConfiguration.

-Make sure the MAPI endpoint and other settings are returned correctly.

4.Check SSL/TLS Certificates

MAPI over HTTP requires valid SSL/TLS certificates. Ensure that the SSL/TLS certificates on your Exchange server are valid and correctly installed. A misconfigured or expired certificate could cause the issue. Make sure the client trusts the certificate as well.

5. Outlook Profile and Client Settings

• Try creating a new Outlook profile for the affected user. A corrupt profile could be the cause of the issue.
• Ensure that the client is set to connect using MAPI over HTTP (and not RPC), which is typically the preferred connection method with Exchange 2016.

6. Restart Exchange Services

Check that the necessary Exchange services are running.

7. Review Logs

• Outlook logs: Enable troubleshooting logging in Outlook (File > Options > Advanced > Enable troubleshooting logging), and check the logs for any specific errors related to MAPI connectivity.
• Exchange Server logs: Check the Event Viewer on the Exchange server for any errors that could indicate issues with MAPI.

8. Firewall and Network Configuration

Verify that there are no firewalls or network restrictions blocking MAPI over HTTP (port 443). Even if IMAP works, MAPI might still be getting blocked or restricted.

9. Test with a Different Profile or Device

If possible, test the user’s account with a different device or create a new Outlook profile to rule out any client-specific issues.

10. Consider Reinstalling Office

As a last resort, try reinstalling Outlook or performing a repair on the Office installation. Sometimes, corrupted Office installations can cause MAPI-related issues.

Hopefully, one of these steps will help resolve the problem. Let me know how it goes or if you need further assistance!

Thanks for confirming that MAPI is enabled for the user. Since the basic configurations are correct, let's try a few more advanced troubleshooting steps:

1. Ensure that MAPI over HTTP is enabled and correctly configured. Sometimes, issues can arise if MAPI over HTTP is not properly set up. You can verify this using the following commands in Exchange Management Shell:

Get-OrganizationConfig | Format-List MapiHttpEnabled

If it's not enabled, you can enable it with:

Set-OrganizationConfig -MapiHttpEnabled $true

2. Verify that the MAPI over HTTP feature is not disabled on the client machine. Check the following registry key:

HKEY_CURRENT_USER\Software\Microsoft\Exchange

Ensure that the MapiHttpDisabled DWORD value is set to 0 or delete the MapiHttpDisabled entry if it exists.

3.Open Outlook and check the connection status by holding down the Ctrl key and right-clicking the Outlook icon in the system tray, then selecting "Connection Status." Ensure that the connection type is MAPI/HTTP.