| 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 |
| 987 | Mapping between X.400 and RFC 822S.E. Kille · obsoleted by RFC 1327, RFC 2156 | Unknown | June 1986 |
| 1026 | Addendum to RFC 987: (Mapping between X.400 and RFC-822)S.E. Kille · obsoleted by RFC 1327, RFC 2156 | Unknown | September 1987 |
| 1123 | Requirements for Internet Hosts - Application and SupportR. Braden, Ed. | Internet Standard | October 1989 |
| 1137 | Mapping between full RFC 822 and RFC 822 with restricted encodingS. Kille | Historic | December 1989 |
| 1138 | Mapping between X.400(1988) / ISO 10021 and RFC 822S.E. Kille · obsoleted by RFC 1327, RFC 2156 | Experimental | December 1989 |
| 1148 | Mapping between X.400(1988) / ISO 10021 and RFC 822S.E. Kille · obsoleted by RFC 1327, RFC 2156 | Experimental | March 1990 |
| 1155 | Structure and identification of management information for TCP/IP-based internetsM.T. Rose, K. McCloghrie | Internet Standard | May 1990 |
| 1278 | A string encoding of Presentation AddressS.E. Hardcastle-Kille | Informational | November 1991 |
| 1327 | Mapping between X.400(1988) / ISO 10021 and RFC 822S. Hardcastle-Kille · obsoleted by RFC 2156 | Proposed Standard | May 1992 |
| 1328 | X.400 1988 to 1984 downgradingS. Hardcastle-Kille | Historic | May 1992 |
| 1484 | Using the OSI Directory to achieve User Friendly Naming (OSI-DS 24 (v1.2))S. Hardcastle-Kille · obsoleted by RFC 1781, RFC 3494 | Historic | July 1993 |
| 1485 | A String Representation of Distinguished Names (OSI-DS 23 (v5))S. Hardcastle-Kille · obsoleted by RFC 1779, RFC 3494 | Historic | July 1993 |
| 1494 | Equivalences between 1988 X.400 and RFC-822 Message BodiesH. Alvestrand, S. Thompson | Historic | August 1993 |
| 1495 | Mapping between X.400 and RFC-822 Message BodiesH. Alvestrand, S. Kille, R. Miles, M. Rose, S. Thompson · obsoleted by RFC 2156 | Proposed Standard | August 1993 |
| 1496 | Rules for downgrading messages from X.400/88 to X.400/84 when MIME content-types are present in the messagesH. Alvestrand, J. Romaguera, K. Jordan | Historic | August 1993 |
| 1522 | MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII TextK. Moore · obsoleted by RFC 2045, RFC 2046, RFC 2047, RFC 2048, RFC 2049 | Draft Standard | September 1993 |
| 1766 | Tags for the Identification of LanguagesH. Alvestrand · obsoleted by RFC 3066, RFC 3282 | Proposed Standard | March 1995 |
| 1891 | SMTP Service Extension for Delivery Status NotificationsK. Moore · obsoleted by RFC 3461 | Proposed Standard | January 1996 |
| 1894 | An Extensible Message Format for Delivery Status NotificationsK. Moore, G. Vaudreuil · obsoleted by RFC 3464 | Proposed Standard | January 1996 |
| 2045 | Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message BodiesN. Freed, N. Borenstein | Draft Standard | November 1996 |
| 2157 | Mapping between X.400 and RFC-822/MIME Message BodiesH. Alvestrand | Proposed Standard | January 1998 |
| 2162 | MaXIM-11 - Mapping between X.400 / Internet mail and Mail-11 mailC. Allocchio | Experimental | January 1998 |
| 2163 | Using the Internet DNS to Distribute MIXER Conformant Global Address Mapping (MCGAM)C. Allocchio | Proposed Standard | January 1998 |
| 2164 | Use of an X.500/LDAP directory to support MIXER address mappingS. Kille | Proposed Standard | January 1998 |