Port 465 — SMTPS

TCP · Port 465/TCP is used for the secure transmission of email messages over a TCP/IP network, utilizing SSL/TLS encryption to ensure confidentiality and integrity. This port is commonly used by mail servers to encrypt SMTP communications with client devices. As a security-relevant service, it plays a crucial role in protecting sensitive email data from interception and eavesdropping.

Port Number: 465
Service Name: SMTPS
Protocol: TCP
Common Software: Postfix, Exim

Security Notes

Review IANA registry for port 465 usage. Apply principle of least privilege - only open ports that are required.

FAQ

What is port 465 used for?

Port 465 is used for SMTPS. Port 465/TCP is used for the secure transmission of email messages over a TCP/IP network, utilizing SSL/TLS encryption to ensure confidentiality and integrity. This port is commonly used by mail servers to encrypt SMTP communications with client devices. As a security-relevant service, it plays a crucial role in protecting sensitive email data from interception and eavesdropping. Common software: Postfix, Exim.

Is port 465 dangerous to leave open?

Review IANA registry for port 465 usage. Apply principle of least privilege - only open ports that are required.

How do I check if port 465 is open?

Use nmap: nmap -p 465 <target> or check locally: ss -tlnp | rg 465