Internet-Security.com TCP port 465 details

TCP port 465 is used for SMTP over implicit TLS, standardized as the “submissions” service in RFC 8314.
Major providers that accept SMTP on 465 include Google’s smtp.gmail.com, Yahoo Mail’s smtp.mail.yahoo.com, Zoho Mail’s smtp.zoho.com, Yandex Mail’s smtp.yandex.com, and AOL’s smtp.aol.com.
Amazon Simple Email Service (SES) also allows SMTP connections on 465 in addition to 25 and 587.
Popular mail transfer agents such as Postfix, Exim (commonly via cPanel), and Sendmail can be configured to listen on 465 for secure message submission.
Mail clients like Microsoft Outlook, Apple Mail, and Mozilla Thunderbird can send mail via 465 when the server offers SMTP SSL.
This port is frequently targeted for SMTP AUTH brute-force and spam relay abuse, so operators commonly enforce strong authentication, rate limiting, and IP reputation controls.

TCP 465