A step-by-step checklist to secure Microsoft Exchange Server:
For Microsoft Exchange Server 2016 (CIS Microsoft Exchange Server 2016 Benchmark version 1.0.0)
CIS has worked with the community since 2010 to publish a benchmark for Microsoft Exchange Server
Join the Microsoft Exchange Server community
Other CIS Benchmark versions:
For Microsoft Exchange Server (CIS Microsoft Exchange Server 2013 Benchmark version 1.1.0)