Email & SMTP

STARTTLS

An SMTP extension that upgrades an existing plaintext connection to encrypted TLS, different from implicit TLS which starts encrypted from the beginning.

Связанные протоколы

SMTP

Упоминается в руководствах

Debugging SMTP Delivery Failures: 4xx Temporary vs 5xx Permanent Debugging & Troubleshooting

SMTP Authentication Methods Explained Email Delivery

RFC 5321: SMTP Protocol Deep Dive Protocol Deep Dives

RFC 959: FTP Protocol Deep Dive Protocol Deep Dives

Связанные сценарии

Email Rejected Due to SPF/DKIM/DMARC Failures SMTP

550 Relay Access Denied — Cannot Send Through SMTP Server SMTP

535 Authentication Failed — App Password Required SMTP

503 Bad Sequence of Commands — AUTH Before STARTTLS SMTP

421 Service Unavailable — STARTTLS Required SMTP

Определено в

RFC 3207 SMTP Service Extension for Secure SMTP over Transport Layer Security

RFC 4217 Securing FTP with TLS

Смотрите также

TLS Handshake Security

SMTP Relay Email & SMTP

MTA (Mail Transfer Agent) Email & SMTP

SMTP Pipelining Email & SMTP

FTPS (FTP Secure) FTP & File Transfer

FTP over TLS (RFC 4217) FTP & File Transfer