Show the expiry date of the installed certificate:
Run as root user:
/opt/zimbra/bin/zmcertmgr viewdeployedcrt all |grep notAfter

Restart all the Zimbra services
Run as zimbra user:
zmcontrol stop ; zmcontrol start

Check the status of all running Zimbra services:
Run as zimbra user:
zmcontrol status

Display the version of the current Zimbra:
Run as zimbra user:
zmcontrol -v