RFC 821: Simple Mail Transfer Protocol

The objective of Simple Mail Transfer Protocol (SMTP) is to transfer mail reliably and efficiently. SMTP is independent of the particular transmission…

Read RFC 821 on the RFC Editor

Outgoing relationships (3 related RFCs)

Obsoletes — RFC 788: Simple Mail Transfer Protocol
Informative reference — RFC 793: Transmission Control Protocol
Informative reference — RFC 822: STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES

Incoming relationships (51 related RFCs)

Showing 50 of 51 related RFCs.

Obsoleted by, Informatively referenced by — RFC 2821: Simple Mail Transfer Protocol
Normatively referenced by — RFC 4409: Message Submission for Mail
Informatively referenced by — RFC 1123: Requirements for Internet Hosts - Application and Support
Informatively referenced by — RFC 4949: Internet Security Glossary, Version 2
Informatively referenced by — RFC 4282: The Network Access Identifier
Informatively referenced by — RFC 5598: Internet Mail Architecture
Informatively referenced by — RFC 1939: Post Office Protocol - Version 3
Informatively referenced by — RFC 1341: MIME (Multipurpose Internet Mail Extensions): Mechanisms for Specifying and Describing the Format of Internet Message Bodies
Informatively referenced by — RFC 2034: SMTP Service Extension for Returning Enhanced Error Codes
Informatively referenced by — RFC 2060: Internet Message Access Protocol - Version 4rev1
Informatively referenced by — RFC 6530: Overview and Framework for Internationalized Email
Informatively referenced by — RFC 987: Mapping between X.400 and RFC 822
Informatively referenced by — RFC 1327: Mapping between X.400(1988) / ISO 10021 and RFC 822
Informatively referenced by — RFC 2554: SMTP Service Extension for Authentication
Informatively referenced by — RFC 934: Proposed standard for message encapsulation
Informatively referenced by — RFC 937: Post Office Protocol: Version 2
Informatively referenced by — RFC 2476: Message Submission
Informatively referenced by — RFC 3030: SMTP Service Extensions for Transmission of Large and Binary MIME Messages
Informatively referenced by — RFC 1113: Privacy enhancement for Internet electronic mail: Part I - message encipherment and authentication procedures
Informatively referenced by — RFC 1160: Internet Activities Board
Informatively referenced by — RFC 1730: Internet Message Access Protocol - Version 4
Informatively referenced by — RFC 1830: SMTP Service Extensions for Transmission of Large and Binary MIME Messages
Informatively referenced by — RFC 1835: Architecture of the WHOIS++ service
Informatively referenced by — RFC 819: The Domain Naming Convention for Internet User Applications
Informatively referenced by — RFC 1492: An Access Control Protocol, Sometimes Called TACACS
Informatively referenced by — RFC 3435: Media Gateway Control Protocol (MGCP) Version 1.0
Informatively referenced by — RFC 1011: Official Internet protocols
Informatively referenced by — RFC 1325: FYI on Questions and Answers Answers to Commonly asked "New Internet User" Questions
Informatively referenced by — RFC 3027: Protocol Complications with the IP Network Address Translator
Informatively referenced by — RFC 1148: Mapping between X.400(1988) / ISO 10021 and RFC 822
Informatively referenced by — RFC 1725: Post Office Protocol - Version 3
Informatively referenced by — RFC 1854: SMTP Service Extension for Command Pipelining
Informatively referenced by — RFC 2167: Referral Whois (RWhois) Protocol V1.5
Informatively referenced by — RFC 1138: Mapping between X.400(1988) / ISO 10021 and RFC 822
Informatively referenced by — RFC 1460: Post Office Protocol - Version 3
Informatively referenced by — RFC 2487: SMTP Service Extension for Secure SMTP over TLS
Informatively referenced by — RFC 2825: A Tangled Web: Issues of I18N, Domain Names, and the Other Internet protocols
Informatively referenced by — RFC 2896: Remote Network Monitoring MIB Protocol Identifier Macros
Informatively referenced by — RFC 915: Network mail path service
Informatively referenced by — RFC 1081: Post Office Protocol: Version 3
Informatively referenced by — RFC 1135: Helminthiasis of the Internet
Informatively referenced by — RFC 1204: Message Posting Protocol (MPP)
Informatively referenced by — RFC 1225: Post Office Protocol: Version 3
Informatively referenced by — RFC 1849: "Son of 1036": News Article Format and Transmission
Informatively referenced by — RFC 2442: The Batch SMTP Media Type
Informatively referenced by — RFC 2626: The Internet and the Millennium Problem (Year 2000)
Informatively referenced by — RFC 840: Official protocols
Informatively referenced by — RFC 961: Official ARPA-Internet protocols
Informatively referenced by — RFC 991: Official ARPA-Internet protocols
Informatively referenced by — RFC 1090: SMTP on X.25