| 793 | Transmission Control ProtocolJ. Postel · obsoleted by RFC 9293 | Internet Standard | September 1981 |
| 821 | Simple Mail Transfer ProtocolJ. Postel · obsoleted by RFC 2821 | Internet Standard | August 1982 |
| 822 | STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGESD. Crocker · obsoleted by RFC 2822 | Internet Standard | August 1982 |
| 937 | Post Office Protocol: Version 2M. Butler, J. Postel, D. Chase, J. Goldberger, J.K. Reynolds | Historic | February 1985 |
| 974 | Mail routing and the domain systemC. Partridge · obsoleted by RFC 2821 | Historic | January 1986 |
| 1034 | Domain names - concepts and facilitiesP. Mockapetris | Internet Standard | November 1987 |
| 1035 | Domain names - implementation and specificationP. Mockapetris | Internet Standard | November 1987 |
| 1047 | Duplicate messages and SMTPC. Partridge | Unknown | February 1988 |
| 1056 | PCMAIL: A distributed mail system for personal computersM.L. Lambert | Informational | June 1988 |
| 1123 | Requirements for Internet Hosts - Application and SupportR. Braden, Ed. | Internet Standard | October 1989 |
| 1652 | SMTP Service Extension for 8bit-MIMEtransportJ. Klensin, N. Freed, M. Rose, E. Stefferud, D. Crocker · obsoleted by RFC 6152 | Draft Standard | July 1994 |
| 1830 | SMTP Service Extensions for Transmission of Large and Binary MIME MessagesG. Vaudreuil · obsoleted by RFC 3030 | Experimental | August 1995 |
| 1847 | Security Multiparts for MIME: Multipart/Signed and Multipart/EncryptedJ. Galvin, S. Murphy, S. Crocker, N. Freed | Proposed Standard | October 1995 |
| 1869 | SMTP Service ExtensionsJ. Klensin, N. Freed, M. Rose, E. Stefferud, D. Crocker · obsoleted by RFC 2821 | Internet Standard | November 1995 |
| 1870 | SMTP Service Extension for Message Size DeclarationJ. Klensin, N. Freed, K. Moore | Internet Standard | November 1995 |
| 1891 | SMTP Service Extension for Delivery Status NotificationsK. Moore · obsoleted by RFC 3461 | Proposed Standard | January 1996 |
| 1893 | Enhanced Mail System Status CodesG. Vaudreuil · obsoleted by RFC 3463 | Proposed Standard | January 1996 |
| 1894 | An Extensible Message Format for Delivery Status NotificationsK. Moore, G. Vaudreuil · obsoleted by RFC 3464 | Proposed Standard | January 1996 |
| 1939 | Post Office Protocol - Version 3J. Myers, M. Rose | Internet Standard | May 1996 |
| 1985 | SMTP Service Extension for Remote Message Queue StartingJ. De Winter | Proposed Standard | August 1996 |
| 2045 | Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message BodiesN. Freed, N. Borenstein | Draft Standard | November 1996 |
| 2047 | MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII TextK. Moore | Draft Standard | November 1996 |
| 2156 | MIXER (Mime Internet X.400 Enhanced Relay): Mapping between X.400 and RFC 822/MIMES. Kille | Proposed Standard | January 1998 |
| 2234 | Augmented BNF for Syntax Specifications: ABNFD. Crocker, Ed., P. Overell · obsoleted by RFC 4234 | Proposed Standard | November 1997 |
| 2298 | An Extensible Message Format for Message Disposition NotificationsR. Fajman · obsoleted by RFC 3798 | Proposed Standard | March 1998 |
| 2373 | IP Version 6 Addressing ArchitectureR. Hinden, S. Deering · obsoleted by RFC 3513 | Proposed Standard | July 1998 |
| 2440 | OpenPGP Message FormatJ. Callas, L. Donnerhacke, H. Finney, R. Thayer · obsoleted by RFC 4880 | Proposed Standard | November 1998 |
| 2476 | Message SubmissionR. Gellens, J. Klensin · obsoleted by RFC 4409 | Proposed Standard | December 1998 |
| 2822 | Internet Message FormatP. Resnick, Ed. · obsoleted by RFC 5322 | Proposed Standard | April 2001 |
| 2979 | Behavior of and Requirements for Internet FirewallsN. Freed | Informational | October 2000 |