Unverified50% confidenceFactExact time
SMTP 协议在设计之初（RFC 821，1982年，由 Jon Postel 撰写）没有考虑身份验证问题，任何人都可以声称自己是任何发件人
1
Sources
50%
Confidence
Long-term
Relevance
8/23/2026
First Seen
Sources
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Related Claims
VerifiedModern email is built on the SMTP protocol, whose core architecture has undergone almost no fundamental changes since the publication of RFC 821 in 1982.76% similarVerifiedThe SMTP protocol was designed without a built-in authentication mechanism, making email spoofing relatively easy to this day and requiring supplementary verification mechanisms such as SPF, DKIM, and DMARC75% similarUnverifiedSMTP协议存在致命缺陷：任何人都可以在邮件的发件人字段填写任意地址74% similarVerifiedSMTP was born in 1982 (RFC 821); the modern version is ESMTP (RFC 5321), and a single session consists of four phases: handshake, authentication, envelope declaration, and data transmission.74% similarVerifiedThe SMTP protocol was born in 1982 and is responsible for the sending and relay transmission of emails.72% similar
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