Port 465SMTPS
Port 465 was initially used for the Secure SMTP (SMTPS) protocol, providing encrypted email transmission via SSL. Despite its early deprecation in favor of STARTTLS on port 587, it has seen a resurgence in use for secured email submissions. This port helps facilitate confidential communication between email clients and servers, ensuring message privacy over potentially insecure networks..
- transport
- tcp
- in transit
- cleartext
- assignment
- unofficial
- risk
- 4/10
- lookups
- 6,041
single transport
payload readable on path
used by convention
caution
rank 823 of 993 · top 83%
1 other service is registered on port 465. compare all 2 →
Technical Details
what runs on :465Originally, port 465 was assigned for SMTPS, which used SSL to secure SMTP transmissions. SSL negotiation begins immediately upon connection, encrypting the entire session from start to finish. This helped to prevent interception or tampering of emails during transit.
However, the IANA revoked the official assignment of port 465 for SMTPS, recommending instead the use of STARTTLS on port 587 to upgrade plaintext SMTP connections to encrypted ones dynamically. Despite this, some mail service providers continued to support port 465 as a convenient means of encrypted submission.
Today, port 465 is widely recognized in practice, offering implicit TLS encryption for SMTP transactions. Clients that connect to this port typically expect an encrypted channel right from connection initiation, differing from the opportunistic nature of STARTTLS on other ports.
Security Information
exposure of :465risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
email averages 3.9 across 42 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
unofficial
used by convention, not registered — what answers here varies by deployment
reachable over
tcp
every listening transport is another surface to filter at the edge
security overview
Common Vulnerabilities
- SSL-related vulnerabilities, especially if outdated protocols like SSLv2 or SSLv3 are supported
- Potential misconfigurations leading to plaintext transmission despite expectation of encryption
- Exploits targeting the SMTP server software, such as buffer overflows or authentication bypass flaws
- Exposure of credentials if weak cipher suites or improper SSL certificate management are used
Common Mitigations
- Enforce use of TLS 1.2 or higher and disable insecure SSL protocols
- Regularly update and patch SMTP server software
- Use strong cipher suites and maintain valid, trusted SSL certificates
- Implement rate limiting, spam filters, and authentication policies to limit abuse
- Employ network firewalls and intrusion detection systems to monitor and control SMTP traffic
Related Ports
the 8 most looked-up other ports in email — 42 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :143 | IMAP | TCPUDP | caution | 20.7k | |
| :995 | POP3S | TCPtls | caution | 18.8k | |
| :109 | POP2 | TCP | caution | 17.9k | |
| :2096 | cPanel SSL Webmail | TCPtls | Web Services | safe | 17.4k |
| :110 | POP3 | TCP | caution | 15.5k | |
| :993 | IMAPS | TCPtls | caution | 14.5k | |
| :1352 | Lotus Notes RPC | TCP | caution | 12.3k | |
| :24 | Private Mail | TCPUDP | caution | 11.7k |
risk mix of the 8 listed
- safe13%
- caution88%
3 of 8 encrypted