Configuring Calendar Server in macOS Server 5 (running on Sierra) is a fairly simple and straight forward process. The Calendar Server is a CalDAV Server, leveraging HTTP and HTTPS, running on ports 8008 and 8443 respectively. To enable the Calendar service in macOS Server 5.2, first open the Server application and click on Calendar in the SERVICES section of the sidebar. Once open, click on Enable invitations by email to enable email notifications of invitations in the Calendar Server. Provide the email address and then click on the Next button. At the Configure Server Email Address screen, provide the type of incoming mail service in use, provide the address of the mail server…