| 10008 | The HTTP QUERY MethodJ. Reschke, J.M. Snell, M. Bishop | Proposed Standard | June 2026 |
| 9580 | OpenPGPP. Wouters, Ed., D. Huigens, J. Winter, Y. Niibe | Proposed Standard | July 2024 |
| 9557 | Date and Time on the Internet: Timestamps with Additional InformationU. Sharma, C. Bormann | Proposed Standard | April 2024 |
| 7103 | Advice for Safe Handling of Malformed MessagesM. Kucherawy, G. Shapiro, N. Freed | Informational | January 2014 |
| 6709 | Design Considerations for Protocol ExtensionsB. Carpenter, B. Aboba, Ed., S. Cheshire | Informational | September 2012 |
| 6648 | Deprecating the "X-" Prefix and Similar Constructs in Application ProtocolsP. Saint-Andre, D. Crocker, M. Nottingham | Best Current Practice | June 2012 |
| 6068 | The 'mailto' URI SchemeM. Duerst, L. Masinter, J. Zawinski | Proposed Standard | October 2010 |
| 5598 | Internet Mail ArchitectureD. Crocker | Informational | July 2009 |
| 5536 | Netnews Article FormatK. Murchison, Ed., C. Lindsey, D. Kohn | Proposed Standard | November 2009 |
| 5364 | Extensible Markup Language (XML) Format Extension for Representing Copy Control Attributes in Resource ListsM. Garcia-Martin, G. Camarillo | Proposed Standard | October 2008 |
| 5337 | Internationalized Delivery Status and Disposition NotificationsC. Newman, A. Melnikov, Ed. · obsoleted by RFC 6533 | Experimental | September 2008 |
| 5336 | SMTP Extension for Internationalized Email AddressesJ. Yao, Ed., W. Mao, Ed. · obsoleted by RFC 6531 | Experimental | September 2008 |
| 5335 | Internationalized Email HeadersA. Yang, Ed. · obsoleted by RFC 6532 | Experimental | September 2008 |
| 5322 | Internet Message FormatP. Resnick, Ed. | Draft Standard | October 2008 |
| 5293 | Sieve Email Filtering: Editheader ExtensionJ. Degener, P. Guenther | Proposed Standard | August 2008 |
| 5260 | Sieve Email Filtering: Date and Index ExtensionsN. Freed | Proposed Standard | July 2008 |
| 5256 | Internet Message Access Protocol - SORT and THREAD ExtensionsM. Crispin, K. Murchison | Proposed Standard | June 2008 |
| 5233 | Sieve Email Filtering: Subaddress ExtensionK. Murchison | Proposed Standard | January 2008 |
| 5231 | Sieve Email Filtering: Relational ExtensionW. Segmuller, B. Leiba | Proposed Standard | January 2008 |
| 5230 | Sieve Email Filtering: Vacation ExtensionT. Showalter, N. Freed, Ed. | Proposed Standard | January 2008 |
| 5228 | Sieve: An Email Filtering LanguageP. Guenther, Ed., T. Showalter, Ed. | Proposed Standard | January 2008 |
| 5173 | Sieve Email Filtering: Body ExtensionJ. Degener, P. Guenther | Proposed Standard | April 2008 |
| 5070 | The Incident Object Description Exchange FormatR. Danyliw, J. Meijer, Y. Demchenko · obsoleted by RFC 7970 | Proposed Standard | December 2007 |
| 5064 | The Archived-At Message Header FieldM. Duerst | Proposed Standard | December 2007 |
| 5031 | A Uniform Resource Name (URN) for Emergency and Other Well-Known ServicesH. Schulzrinne | Proposed Standard | January 2008 |
| 5016 | Requirements for a DomainKeys Identified Mail (DKIM) Signing Practices ProtocolM. Thomas | Informational | October 2007 |
| 5000 | Internet Official Protocol StandardsRFC Editor · obsoleted by RFC 7100 | Historic | May 2008 |
| 4997 | Formal Notation for RObust Header Compression (ROHC-FN)R. Finking, G. Pelletier | Proposed Standard | July 2007 |
| 4952 | Overview and Framework for Internationalized EmailJ. Klensin, Y. Ko · obsoleted by RFC 6530 | Informational | July 2007 |
| 4880 | OpenPGP Message FormatJ. Callas, L. Donnerhacke, H. Finney, D. Shaw, R. Thayer · obsoleted by RFC 9580 | Proposed Standard | November 2007 |
| 4871 | DomainKeys Identified Mail (DKIM) SignaturesE. Allman, J. Callas, M. Delany, M. Libbey, J. Fenton, M. Thomas · obsoleted by RFC 6376 | Proposed Standard | May 2007 |
| 4870 | Domain-Based Email Authentication Using Public Keys Advertised in the DNS (DomainKeys)M. Delany · obsoleted by RFC 4871 | Historic | May 2007 |
| 4865 | SMTP Submission Service Extension for Future Message ReleaseG. White, G. Vaudreuil | Proposed Standard | May 2007 |
| 4823 | FTP Transport for Secure Peer-to-Peer Business Data Interchange over the InternetT. Harding, R. Scott | Informational | April 2007 |
| 4790 | Internet Application Protocol Collation RegistryC. Newman, M. Duerst, A. Gulbrandsen | Proposed Standard | March 2007 |
| 4765 | The Intrusion Detection Message Exchange Format (IDMEF)H. Debar, D. Curry, B. Feinstein | Experimental | March 2007 |
| 4718 | IKEv2 Clarifications and Implementation GuidelinesP. Eronen, P. Hoffman · obsoleted by RFC 5996 | Informational | October 2006 |
| 4686 | Analysis of Threats Motivating DomainKeys Identified Mail (DKIM)J. Fenton | Informational | September 2006 |
| 4685 | Atom Threading ExtensionsJ. Snell | Proposed Standard | September 2006 |
| 4566 | SDP: Session Description ProtocolM. Handley, V. Jacobson, C. Perkins · obsoleted by RFC 8866 | Proposed Standard | July 2006 |
| 4524 | COSINE LDAP/X.500 SchemaK. Zeilenga, Ed. | Proposed Standard | June 2006 |
| 4505 | Anonymous Simple Authentication and Security Layer (SASL) MechanismK. Zeilenga | Proposed Standard | June 2006 |
| 4475 | Session Initiation Protocol (SIP) Torture Test MessagesR. Sparks, Ed., A. Hawrylyshen, A. Johnston, J. Rosenberg, H. Schulzrinne | Informational | May 2006 |
| 4469 | Internet Message Access Protocol (IMAP) CATENATE ExtensionP. Resnick | Proposed Standard | April 2006 |
| 4463 | A Media Resource Control Protocol (MRCP) Developed by Cisco, Nuance, and SpeechworksS. Shanmugham, P. Monaco, B. Eberman | Informational | April 2006 |
| 4416 | Goals for Internet Messaging to Support Diverse Service EnvironmentsJ. Wong, Ed. | Informational | February 2006 |
| 4409 | Message Submission for MailR. Gellens, J. Klensin · obsoleted by RFC 6409 | Draft Standard | April 2006 |
| 4408 | Sender Policy Framework (SPF) for Authorizing Use of Domains in E-Mail, Version 1M. Wong, W. Schlitt · obsoleted by RFC 7208 | Experimental | April 2006 |
| 4407 | Purported Responsible Address in E-Mail MessagesJ. Lyon | Historic | April 2006 |
| 4406 | Sender ID: Authenticating E-MailJ. Lyon, M. Wong | Historic | April 2006 |
| 4405 | SMTP Service Extension for Indicating the Responsible Submitter of an E-Mail MessageE. Allman, H. Katz | Historic | April 2006 |
| 4398 | Storing Certificates in the Domain Name System (DNS)S. Josefsson | Proposed Standard | March 2006 |
| 4356 | Mapping Between the Multimedia Messaging Service (MMS) and Internet MailR. Gellens | Proposed Standard | January 2006 |
| 4324 | Calendar Access Protocol (CAP)D. Royer, G. Babics, S. Mansour | Experimental | December 2005 |
| 4287 | The Atom Syndication FormatM. Nottingham, Ed., R. Sayre, Ed. | Proposed Standard | December 2005 |
| 4249 | Implementer-Friendly Specification of Message and MIME-Part Header Fields and Field ComponentsB. Lilly | Informational | January 2006 |
| 4239 | Internet Voice Messaging (IVM)S. McRae, G. Parsons | Proposed Standard | November 2005 |
| 4161 | Guidelines for Optional Services for Internet Fax GatewaysK. Mimura, K. Yokoyama, T. Satoh, K. Watanabe, C. Kanaide | Informational | September 2005 |
| 4160 | Internet Fax Gateway RequirementsK. Mimura, K. Yokoyama, T. Satoh, C. Kanaide, C. Allocchio | Informational | September 2005 |
| 4155 | The application/mbox Media TypeE. Hall | Informational | September 2005 |
| 4141 | SMTP and MIME Extensions for Content ConversionK. Toyoda, D. Crocker | Proposed Standard | November 2005 |
| 4130 | MIME-Based Secure Peer-to-Peer Business Data Interchange Using HTTP, Applicability Statement 2 (AS2)D. Moberg, R. Drummond | Proposed Standard | July 2005 |
| 4096 | Policy-Mandated Labels Such as "Adv:" in Email Subject Headers Considered Ineffective At BestC. Malamud | Informational | May 2005 |
| 4024 | Voice Messaging Client BehaviourG. Parsons, J. Maruszak | Informational | July 2005 |
| 4021 | Registration of Mail and MIME Header FieldsG. Klyne, J. Palme | Proposed Standard | March 2005 |
| 3977 | Network News Transfer Protocol (NNTP)C. Feather | Proposed Standard | October 2006 |
| 3974 | SMTP Operational Experience in Mixed IPv4/v6 EnvironmentsM. Nakamura, J. Hagino | Informational | January 2005 |
| 3965 | A Simple Mode of Facsimile Using Internet MailK. Toyoda, H. Ohno, J. Murai, D. Wing | Draft Standard | December 2004 |
| 3939 | Calling Line Identification for Voice Mail MessagesG. Parsons, J. Maruszak | Proposed Standard | December 2004 |
| 3930 | The Protocol versus Document Points of View in Computer ProtocolsD. Eastlake 3rd | Informational | October 2004 |
| 3922 | Mapping the Extensible Messaging and Presence Protocol (XMPP) to Common Presence and Instant Messaging (CPIM)P. Saint-Andre | Proposed Standard | October 2004 |
| 3892 | The Session Initiation Protocol (SIP) Referred-By MechanismR. Sparks | Proposed Standard | September 2004 |
| 3886 | An Extensible Message Format for Message Tracking ResponsesE. Allman | Proposed Standard | September 2004 |
| 3865 | A No Soliciting Simple Mail Transfer Protocol (SMTP) Service ExtensionC. Malamud | Proposed Standard | September 2004 |
| 3864 | Registration Procedures for Message Header FieldsG. Klyne, M. Nottingham, J. Mogul | Best Current Practice | September 2004 |
| 3862 | Common Presence and Instant Messaging (CPIM): Message FormatG. Klyne, D. Atkins | Proposed Standard | August 2004 |
| 3860 | Common Profile for Instant Messaging (CPIM)J. Peterson | Proposed Standard | August 2004 |
| 3859 | Common Profile for Presence (CPP)J. Peterson | Proposed Standard | August 2004 |
| 3850 | Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.1 Certificate HandlingB. Ramsdell, Ed. · obsoleted by RFC 5750 | Proposed Standard | July 2004 |
| 3842 | A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP)R. Mahy | Proposed Standard | August 2004 |
| 3834 | Recommendations for Automatic Responses to Electronic MailK. Moore | Proposed Standard | August 2004 |
| 3805 | Printer MIB v2R. Bergman, H. Lewis, I. McDonald | Proposed Standard | June 2004 |
| 3804 | Voice Profile for Internet Mail (VPIM) AddressingG. Parsons | Proposed Standard | June 2004 |
| 3795 | Survey of IPv4 Addresses in Currently Deployed IETF Application Area Standards Track and Experimental DocumentsR. Sofia, P. Nesser, II | Informational | June 2004 |
| 3773 | High-Level Requirements for Internet Voice MailE. Candell | Informational | June 2004 |
| 3733 | Extensible Provisioning Protocol (EPP) Contact MappingS. Hollenbeck · obsoleted by RFC 4933 | Proposed Standard | March 2004 |
| 3696 | Application Techniques for Checking and Transformation of NamesJ. Klensin | Informational | February 2004 |
| 3675 | .sex Considered DangerousD. Eastlake 3rd | Informational | February 2004 |
| 3599 | Request for Comments Summary RFC Numbers 3500-3599S. Ginoza | Informational | December 2003 |
| 3598 | Sieve Email Filtering -- Subaddress ExtensionK. Murchison · obsoleted by RFC 5233 | Proposed Standard | September 2003 |
| 3550 | RTP: A Transport Protocol for Real-Time ApplicationsH. Schulzrinne, S. Casner, R. Frederick, V. Jacobson | Internet Standard | July 2003 |
| 3536 | Terminology Used in Internationalization in the IETFP. Hoffman · obsoleted by RFC 6365 | Informational | May 2003 |
| 3507 | Internet Content Adaptation Protocol (ICAP)J. Elson, A. Cerpa | Informational | April 2003 |
| 3502 | Internet Message Access Protocol (IMAP) - MULTIAPPEND ExtensionM. Crispin | Proposed Standard | March 2003 |
| 3501 | INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1M. Crispin · obsoleted by RFC 9051 | Proposed Standard | March 2003 |
| 3499 | Request for Comments Summary RFC Numbers 3400-3499S. Ginoza | Informational | December 2003 |
| 3490 | Internationalizing Domain Names in Applications (IDNA)P. Faltstrom, P. Hoffman, A. Costello · obsoleted by RFC 5890, RFC 5891 | Proposed Standard | March 2003 |
| 3458 | Message Context for Internet MailE. Burger, E. Candell, C. Eliot, G. Klyne | Proposed Standard | January 2003 |
| 3431 | Sieve Extension: Relational TestsW. Segmuller · obsoleted by RFC 5231 | Proposed Standard | December 2002 |
| 3391 | The MIME Application/Vnd.pwg-multiplexed Content-TypeR. Herriot | Informational | December 2002 |
| 3339 | Date and Time on the Internet: TimestampsG. Klyne, C. Newman | Proposed Standard | July 2002 |
| 3335 | MIME-based Secure Peer-to-Peer Business Data Interchange over the InternetT. Harding, R. Drummond, C. Shih | Proposed Standard | September 2002 |
| 3297 | Content Negotiation for Messaging Services based on EmailG. Klyne, R. Iwazaki, D. Crocker | Proposed Standard | July 2002 |
| 3283 | Guide to Internet CalendaringB. Mahoney, G. Babics, A. Taler | Informational | July 2002 |
| 3282 | Content Language HeadersH. Alvestrand | Draft Standard | May 2002 |
| 3261 | SIP: Session Initiation ProtocolJ. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler | Proposed Standard | July 2002 |
| 3259 | A Message Bus for Local CoordinationJ. Ott, C. Perkins, D. Kutscher | Informational | May 2002 |
| 3249 | Implementers Guide for Facsimile Using Internet MailV. Cancio, M. Moldovan, H. Tamura, D. Wing | Informational | September 2002 |
| 3192 | Minimal FAX address format in Internet MailC. Allocchio | Draft Standard | October 2001 |
| 3191 | Minimal GSTN address format in Internet MailC. Allocchio | Draft Standard | October 2001 |
| 2919 | List-Id: A Structured Field and Namespace for the Identification of Mailing ListsR. Chandhok, G. Wenger | Proposed Standard | March 2001 |
| 2821 | Simple Mail Transfer ProtocolJ. Klensin, Ed. · obsoleted by RFC 5321 | Proposed Standard | April 2001 |
| 1849 | "Son of 1036": News Article Format and TransmissionH. Spencer · obsoleted by RFC 5536, RFC 5537 | Historic | March 2010 |