I am replacing by Exchange 2010 Hybrid Exchange server with Exchange 2016 Hybrid servers. I have no on-premise mailboxes -- only Office 365 mailboxes. The on-premise servers are for bulk and anonymous sending, management, web redirection to Office. In the past I've had trouble with IIS reconfiguring itself after patches and updates. I'd like to omit IIS activities from configuration and simplify. Would it be possible to setup a load balancer to redirect mail.domain.com to outlook.com/owa/domainname.com and not configure IIS. I know the smtp sending wouldn't be effected, but I'm not clear on autodiscover,activesync, etc. and how they might be effected. All the web articles I'm seeing show setting virtual directories for autodiscover,activesync,owa, etc. - what is the purpose of these virtual directories and are they necessary for a no on-premise maibox hybrid install.What do I need to test for on-premise clients? Thanks in advance.