Mac OS Sierra Mail app was acting strange so I removed all accounts and now I'm trying to add them again.  I use EAS and EWS, in the Mac Mail App I select Exchange.  Enter my full email and password.  It goes offline as it can't connect.  It's trying to use the left part of the email (excluding domain) as the username and I believe SM requires the full email address.  Not sure if this is something new in macOS Sierra or if this is a configuration error on the server I need to find or a SM bug with EWS?

 

Is there a way to set the default domain for signing in to SM so we don't have to use the full email address as the username?  I guess there could be conflicts with the same username across domains through.

 

Anywho, mail (EWS) is not working in sierra!