| 1870 | SMTP Service Extension for Message Size DeclarationJ. Klensin, N. Freed, K. Moore | Internet Standard | November 1995 |
| 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 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 2231 | MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and ContinuationsN. Freed, K. Moore | Proposed Standard | November 1997 |
| 2369 | The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header FieldsG. Neufeld, J. Baer | Proposed Standard | July 1998 |
| 2392 | Content-ID and Message-ID Uniform Resource LocatorsE. Levinson | Proposed Standard | August 1998 |
| 2557 | MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)J. Palme, A. Hopmann, N. Shelness | Proposed Standard | March 1999 |
| 2852 | Deliver By SMTP Service ExtensionD. Newman | Proposed Standard | June 2000 |
| 3282 | Content Language HeadersH. Alvestrand | Draft Standard | May 2002 |
| 3461 | Simple Mail Transfer Protocol (SMTP) Service Extension for Delivery Status Notifications (DSNs)K. Moore | Draft Standard | January 2003 |
| 3463 | Enhanced Mail System Status CodesG. Vaudreuil | Draft Standard | January 2003 |
| 3464 | An Extensible Message Format for Delivery Status NotificationsK. Moore, G. Vaudreuil | Draft Standard | January 2003 |
| 3501 | INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1M. Crispin · obsoleted by RFC 9051 | Proposed Standard | March 2003 |
| 3834 | Recommendations for Automatic Responses to Electronic MailK. Moore | Proposed Standard | August 2004 |
| 4314 | IMAP4 Access Control List (ACL) ExtensionA. Melnikov | Proposed Standard | December 2005 |
| 4422 | Simple Authentication and Security Layer (SASL)A. Melnikov, Ed., K. Zeilenga, Ed. | Proposed Standard | June 2006 |
| 4616 | The PLAIN Simple Authentication and Security Layer (SASL) MechanismK. Zeilenga, Ed. | Proposed Standard | August 2006 |
| 4865 | SMTP Submission Service Extension for Future Message ReleaseG. White, G. Vaudreuil | Proposed Standard | May 2007 |
| 4954 | SMTP Service Extension for AuthenticationR. Siemborski, Ed., A. Melnikov, Ed. | Proposed Standard | July 2007 |
| 5198 | Unicode Format for Network InterchangeJ. Klensin, M. Padlipsky | Proposed Standard | March 2008 |
| 5248 | A Registry for SMTP Enhanced Mail System Status CodesT. Hansen, J. Klensin | Best Current Practice | June 2008 |
| 5256 | Internet Message Access Protocol - SORT and THREAD ExtensionsM. Crispin, K. Murchison | Proposed Standard | June 2008 |
| 5321 | Simple Mail Transfer ProtocolJ. Klensin | Draft Standard | October 2008 |
| 5322 | Internet Message FormatP. Resnick, Ed. | Draft Standard | October 2008 |
| 5788 | IMAP4 Keyword RegistryA. Melnikov, D. Cridland | Proposed Standard | March 2010 |
| 6154 | IMAP LIST Extension for Special-Use MailboxesB. Leiba, J. Nicolson | Proposed Standard | March 2011 |
| 6409 | Message Submission for MailR. Gellens, J. Klensin | Internet Standard | November 2011 |
| 6532 | Internationalized Email HeadersA. Yang, S. Steele, N. Freed | Proposed Standard | February 2012 |
| 6533 | Internationalized Delivery Status and Disposition NotificationsT. Hansen, Ed., C. Newman, A. Melnikov | Proposed Standard | February 2012 |
| 6710 | Simple Mail Transfer Protocol Extension for Message Transfer PrioritiesA. Melnikov, K. Carlberg | Proposed Standard | August 2012 |
| 7489 | Domain-based Message Authentication, Reporting, and Conformance (DMARC)M. Kucherawy, Ed., E. Zwicky, Ed. · obsoleted by RFC 9989, RFC 9990, RFC 9991 | Informational | March 2015 |
| 7677 | SCRAM-SHA-256 and SCRAM-SHA-256-PLUS Simple Authentication and Security Layer (SASL) MechanismsT. Hansen | Proposed Standard | November 2015 |
| 7841 | RFC Streams, Headers, and BoilerplatesJ. Halpern, Ed., L. Daigle, Ed., O. Kolkman, Ed. | Informational | May 2016 |
| 8098 | Message Disposition NotificationT. Hansen, Ed., A. Melnikov, Ed. | Internet Standard | February 2017 |
| 8174 | Ambiguity of Uppercase vs Lowercase in RFC 2119 Key WordsB. Leiba | Best Current Practice | May 2017 |
| 8314 | Cleartext Considered Obsolete: Use of Transport Layer Security (TLS) for Email Submission and AccessK. Moore, C. Newman | Proposed Standard | January 2018 |
| 8457 | IMAP "$Important" Keyword and "\Important" Special-Use AttributeB. Leiba, Ed. | Proposed Standard | September 2018 |
| 8474 | IMAP Extension for Object IdentifiersB. Gondwana, Ed. | Proposed Standard | September 2018 |
| 8620 | The JSON Meta Application Protocol (JMAP)N. Jenkins, C. Newman | Proposed Standard | July 2019 |