Does 5.6.3 delete deprecated services? - Apple Support Community
(Mail, DNS, DHCP, VPN, Websites, Wiki, Calendar, Contacts) macOS Server 5.6.3
It served as a preparation point for the subsequent macOS Mojave-compatible version (5.7.1), which removed the vast majority of server features. The "Deprecated Services" Turning Point Does 5
As a legacy version, 5.6.3 has developed several significant maintenance challenges for those still running it: macOS Server 5.6.3
This version is the ultimate release for macOS High Sierra 10.13.6 .