Standard Zimbra ports
| SMTP | 25 | tcp | |
| HTTP | 80 | tcp | |
| POP3 | 110 | tcp | |
| IMAP | 143 | tcp | should probably be limited by a firewall to your local network only |
| LDAP | 389 | tcp | |
| HTTPS | 443 | tcp | |
| SMTPS | 465 | tcp | |
| IMAPS | 993 | tcp | |
| POP3S | 995 | tcp | |
| (Admin Interface) | 7071 | tcp | should probably be limited by a firewall to your local network only |
| LMTP | 7025 | tcp | should probably be limited by a firewall to your local network only |
source :
Because It Works!! 