← Port Encyclopedia
25
SMTP
TCP
Email
High Risk
Simple Mail Transfer Protocol — email relay, open relay abuse, spam vector
🔍 How to Scan Port 25
nmap -sV -p 25 target
nmap -sV -sC --script=banner -p 25 target
nc -zv target 25
🛡️ Security Considerations
- Scan port 25 with
nmap -sVto identify the exact service and version - If SMTP is not needed, close or firewall this port immediately
- Check for default credentials if a management interface runs on this port
- Use
searchsploit smtpto find known exploits - Monitor traffic on port 25 with Wireshark or tcpdump for anomalies
- Ensure the service is patched to the latest version to prevent known CVE exploitation