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Port 465SMTP over SSL

Port 465 is commonly used for secure SMTP communication, encapsulating email transmission within SSL encryption. This port facilitates encrypted email delivery between clients and mail servers, enhancing privacy compared to traditional plain-text SMTP connections. Although it was initially designated as a secure SMTP port, its status has shifted over time, but it remains widely supported for legacy encrypted email connections..

inEmailSecurityNetwork Services
transport
tcp

single transport

in transit
encrypted

payload protected on the wire

assignment
unofficial

used by convention

risk
4/10

caution

lookups
10,421

rank 431 of 993 · top 43%

1 other service is registered on port 465. compare all 2 →

Technical Details

what runs on :465

SMTP over SSL, associated with port 465, was originally registered for secure SMTP submissions where SSL/TLS encryption is used to protect email exchanges. Unlike opportunistic STARTTLS, which upgrades an insecure connection, SMTP over SSL initiates a secure, encrypted connection from the outset known as implicit TLS. This design ensures all communication on the connection remains confidential and resistant to passive eavesdropping.

Historically, port 465 was briefly assigned as the standard for SMTPS. However, this designation was revoked in favor of submission via port 587 using STARTTLS. Despite its deprecated official status, many email service providers continue supporting port 465 as a default for implicit SSL/TLS due to widespread client compatibility and legacy support.

Modern email infrastructure typically favors port 587 or 25 with STARTTLS for MTA-to-MTA and client-to-server interactions. Yet, port 465 persists as a method of securely conveying credentials and message data during submission, especially in older or consumer-grade email clients. Administrators should be aware of its deprecated status but also recognize its ongoing practical usage.

Security Information

exposure of :465

risk 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

encrypted

payloads are protected on the wire

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:

  • Misconfigurations can leave SSL protocols outdated and susceptible to attacks such as POODLE or BEAST.
  • Use of weak cipher suites may expose data transmissions to decryption attempts.
  • Certificate validation failures might allow Man-in-the-Middle attacks, undermining encryption benefits.
  • Brute-force login attempts targeting email credentials.

Common Mitigations:

  • Enforce modern, secure TLS protocols (TLS 1.2 or higher) and disable deprecated SSL versions.
  • Implement strong cipher suites with Perfect Forward Secrecy.
  • Use valid, trusted certificates and enable strict certificate validation.
  • Deploy rate limiting, IP reputation services, and MFA where possible to protect against brute-force attacks.
  • Monitor authentication attempts and analyze logs for signs of unusual or malicious activity.

Related Ports

all 42 in email →

the 8 most looked-up other ports in email — 42 ports carry that label.

portservicerisk
:143IMAPcaution
:995POP3Scaution
:109POP2caution
:2096cPanel SSL Webmailsafe
:110POP3caution
:993IMAPScaution
:1352Lotus Notes RPCcaution
:24Private Mailcaution

risk mix of the 8 listed

  • safe13%
  • caution88%

3 of 8 encrypted