@smitty @sarb I remember that was literally what services such as Microsoft Network (MSN) were all about in their first iterations and what Exchange server was originally for.
Their idea was you would access everything through their network and stay on their network for the most part with proprietary systems for messages and "web" and a "gateway" that they could charge you for to access other networks such as AOL, Compuserve, or "internet messages".
@PeaEyeEnnKay @smitty I know! Remember when the person who knew how to interface with the Exchange server was the person who you had to suck up to the most in order to get anything down outside the internal network?