Ports are software gateways that require cPanel servers to function properly to be open by the firewall. 20 — FTP TCP inbound/outbound 21 — FTP TCP, UDP inbound/outbound 22 — SSH TCP inbound 25 — SMTP TCP inbound/outbound 26 — SMTP TCP inbound/outbound 37 — rdate TCP outbound 43 — whois TCP outbound 53 — DNS TCP/UDP inbound/outbound (inbound is only needed if you run your own public DNS server) 80 — HTTP TCP inbound/outbound 110 — POP3 TCP inbound 113 — ident TCP outbound 143 — IMAP4 TCP inbound 443 — HTTPS TCP inbound 465 — SMTP TLS/SSL TCP/UDP inbound/outbound 783 — SpamAssassin TCP/UDP inbound 873 — rsync TCP/UDP outbound 993 — IMAP4 SSL TCP inbound 995 — POP3 SSL TCP inbound 2077 — WebDAV TCP/UDP inbound/outbound 2078 — WebDAV SSL TCP/UDP inbound/outbound 2082 — cPanel TCP inbound 2083 — cPanel SSL TCP inbound 2086 — WHM TCP inbound 2087 — WHM SSL TCP inbound 2089 — cPanel license TCP outbound 2095 — Webmail TCP inbound 2096 — Webmail SSL TCP in...