Help Needed trying to set up Email

I have now spend 3 frustrating days trying to configure emails .. and am no closer than when I started .. frustrated.com!

CRM Dynamice365 on-premises

Outlook 365

Currently there are only two users on the system, admin and one other. What I want to do  (if possible) is to only have CRM  send and receive everything from one email address ( ie support email)

I have tried so many tutorials which show different ways of doing things, but cannot get any to work ... I cannot even work out how to hook up to outlook 365

I have rolled back my VS machine so I am back to having the email router installed but not configured

 if anyone could possible guide me through how to set up the email router,  I would be eternally grateful