Sync Service unable to connect Azure/O365 via a Proxy (4272084)

When configuring the Synch Service to connect to Azure via a Proxy, an error such as this example may be encountered when clicking Test Connection:

"Connecting to remote server ps.outlook.com failed with the following error message: The client cannot connect to the destination specified in the request.

Verify that the service on the destination is running and is accepting requests. Consult the logs and documentation for the WS-Management service running on the destination, most commonly IIS or WinRM.

If the destination is the WinRM service, run the following command on the destination to analyze and configure the WinRM service: "winrm quickconfig". For more information, see the about_Remote_Troubleshooting Help topic.." “

WORKAROUND
 

1. Ensure the O365 account used is enabled for Remote PowerShell (note: you may need to load the Exchange PowerShell module and connect to tenet beforehand):

set-user -RemotePowerShellEnabled $True

2. Check if a Proxy Server been configured for WinRM:

netsh winhttp show proxy
 

3. If the result of Step 2 is an expired proxy server, reset its settings and configure a new proxy server for WinRM using this commands below:

netsh winhttp reset proxy

netsh winhttp set proxy proxyservername:portnumber

NOTE: replace proxyservername with either a name or ip. Change portnumber to the appropriate port such as 8080.