Network Port: 465
Network Port Reference Guide
Registered Service Name
SMTP over SSL (SMTPS)
Transport Protocol
TCP
Functional Overview
Port 465 was originally allocated for SMTP over SSL (SMTPS). It is commonly used for secure mail submission.
Security Risks & Vulnerabilities
Ensure strong certificate validation. Prefer Port 587 with STARTTLS or implicit SSL on 465 depending on client compatibility.
How to audit network port status
1. Scan Open Ports: Use our Port Scanner utility to verify if this port is actively listening on your host.
2. Verify Encryption: Audit the service layer to confirm SSL/TLS is protecting transmission payload.
3. Hardening Rules: Apply the firewall instructions below to shut down unauthorized inbound ports.
UFW Firewall Rules
Allow Command
sudo ufw allow 465/tcp
Block Command
sudo ufw deny 465/tcp
iptables Firewall Rules
Allow Command
sudo iptables -A INPUT -p tcp --dport 465 -j ACCEPT
Block Command
sudo iptables -A INPUT -p tcp --dport 465 -j DROP