Wanted to share a great tool from Microsoft (I sound like it’s a sponsored tutorial) which has helped me a great deal in troubleshooting costumers migration from GSuite to Exchange Online.
To be honest, my problem was with the Outlook Autodiscover feature and this tool put me in the right direction. Btw, Autodiscover service is to establish initial connections to Exchange user mailboxes.
Tool is called Microsoft Remote Connectivity Analyzer and you can visit it here -> https://testconnectivity.microsoft.com/
This tool is not just for Microsoft Exchange tests, it also includes troubleshooting for Lync, Office365 etc. Be sure to have all the right usernames and passwords.