Based on your error message, you’re attempting to connect Outlook for Mac to an Exchange server that doesn’t meet the minimum requirements. Office 365, of course, should be the latest and greatest if you’re using its Exchange Online service.
Are you attempting to connect to an Exchange server account that’s not part of Office 365? If so, does it meet the minimum requirements mentioned in the alert message?
Are you attempting to connect to an Office 365 account (not Outlook.com)? If so, are you allowing Outlook to auto configure your settings or are you entering the settings manually? The server address for Office 365 is “outlook.office365.com”.
Are you possibly needing to connect to a non-Exchange account such as POP or IMAP? If so, do not choose Exchange as the type of email account you’re trying to configure. Choose E-mail instead.
Hope this helps!