How to Disable Pop3 protocol in Zimbra Server

Check status of pop3 server on server label
$ zmprov gs `zmhostname` | grep zimbraPop3ServerEnabled
zimbraPop3ServerEnabled: TRUE

Disable service on server
$ zmprov ms `zmhostname` zimbraPop3ServerEnabled FALSE

Now disable attribute for COS and account
$ zmprov mc default zimbraPop3Enabled FALSE

Check status of COS
$ zmprov gc default | grep  zimbraPop3Enabled
zimbraPop3Enabled: FALSE

Check status  for an account
$ zmprov -l ga shahzad@linuxsolution.in | grep -i zimbraPop3Enabled

If you require to enable pop3 for a user, you can enable.
$ zmprov ma shahzad@linuxsolution.in zimbraPop3Enabled TRUE

Now again check status
$ zmprov -l ga shahzad@linuxsolution.in | grep -i zimbraPop3Enabled
zimbraPop3Enabled: TRUE

Ref:

http://shahzadlinux.blogspot.com/2017/05/how-to-disable-pop3-in-zimbra-server.html