SourceS-0017
SMTP — RFC 821 (1982) and RFC 5321 (2008)
References [17]2026-05-030 out · 1 in
Postel, J. Simple Mail Transfer Protocol. RFC 821, IETF, August 1982. Klensin, J. RFC 5321, IETF, October 2008.
Use: Foundational protocol specification for email. RFC 821 establishes the 44-year operational lineage cited in C-0013 and E-0008. RFC 5321 is the current canonical specification.
Original whitepaper reference: [17]