please check the attached Doc for network Diagram
B1 /B2 ( workgroup),B3 / B4 (AD) are braches . b3 and b4 have their own local AD and DNS . Head of has the abc.com and same name registered externaly(public). Currently head office users got all the option to get connected to exchange mail boxes in Head office . unfortunately branch level only can access OWA by entering ipaddress\owa . but I want to go with the proper name resolving way .
I tried accessing via outlook any ware from the branch office . it seems to me that same issue like name thing .
When I configure the port 443 as ssl . this will resolve ? we are accessing head office via telikom and isp Data ip VPN
Please let me know the best way go with my branch mail setup (client)