Users need to consider whether they have the resources, expertise, and body of knowledge to continue supporting an on-premises server. Many more organizations are moving to Microsoft 365 as this places the burden of patching, installing, and day-to-day maintenance on Microsoft.
While the CIS Benchmarks will still help you guide secure deployment of an on-premises server, it doesn’t reflect the fact that the number of companies and businesses that use on-premise Microsoft mail servers is shrinking. It’s worth considering whether an organization has the community resources within and the necessary vendor support to stay with an on-premises mail server.
That isn’t to say that if you migrate to a cloud mail server in the form of Microsoft 365 your security issues will immediately cease to exist. Rather, you go from focusing on maintenance and deployment to protecting and securing authentication to your cloud assets. More vendors and consultants are moving towards supporting and knowing the Microsoft 365 platform better than an on-premises solution.
