On CentOS 7 server with firewalld running, used following command to open ports used by Zimbra Mail Server.
firewall-cmd --zone=public --permanent --add-service=http firewall-cmd --zone=public --permanent --add-service=https firewall-cmd --zone=public --permanent --add-service=ssh firewall-cmd --zone=public --permanent --add-port=110/tcp firewall-cmd --zone=public --permanent --add-port=11211/tcp firewall-cmd --zone=public --permanent --add-port=143/tcp firewall-cmd --zone=public --permanent --add-port=25/tcp firewall-cmd --zone=public --permanent --add-port=443/tcp firewall-cmd --zone=public --permanent --add-port=465/tcp firewall-cmd --zone=public --permanent --add-port=5222/tcp firewall-cmd --zone=public --permanent --add-port=5269/tcp firewall-cmd --zone=public --permanent --add-port=587/tcp firewall-cmd --zone=public --permanent --add-port=7025/tcp firewall-cmd --zone=public --permanent --add-port=7071/tcp firewall-cmd --zone=public --permanent --add-port=7072/tcp firewall-cmd --zone=public --permanent --add-port=7073/tcp firewall-cmd --zone=public --permanent --add-port=7110/tcp firewall-cmd --zone=public --permanent --add-port=7143/tcp firewall-cmd --zone=public --permanent --add-port=7993/tcp firewall-cmd --zone=public --permanent --add-port=7995/tcp firewall-cmd --zone=public --permanent --add-port=8443/tcp firewall-cmd --zone=public --permanent --add-port=993/tcp firewall-cmd --zone=public --permanent --add-port=995/tcp firewall-cmd --reload
See Zimbra, firewall-cmd
