I found this article series extremely helpful where you want to publish Exchange and also want to publish ADFS servers for Office 365 SSO using  free IIS Application Request Routing proxy server.

Part 1 : Reverse Proxy for Exchange Server 2013 using IIS ARR

Part 2: Reverse Proxy for Exchange Server 2013 using IIS ARR

Part 3: Reverse Proxy for Exchange Server 2013 using IIS ARR

Part 4: IIS ARR as a Reverse Proxy and Load balancing solution for O365 Exchange Online in a Hybrid Configuration

Happy Reverse proxy