| 10003 | Certificate Management over CMS (CMC): Transport ProtocolsJ. Mandel, Ed., S. Turner, Ed. | Proposed Standard | July 2026 |
| 9787 | Guidance on End-to-End Email SecurityD. K. Gillmor, Ed., A. Melnikov, Ed., B. Hoeneisen, Ed. | Informational | August 2025 |
| 9623 | Implementing Interfaces to Transport ServicesA. Brunstrom, Ed., T. Pauly, Ed., R. Enghardt, P.S. Tiesel, M. Welzl | Informational | January 2025 |
| 9422 | The LIMITS SMTP Service ExtensionN. Freed, J. Klensin | Proposed Standard | February 2024 |
| 8744 | Issues and Requirements for Server Name Identification (SNI) Encryption in TLSC. Huitema | Informational | July 2020 |
| 8689 | SMTP Require TLS OptionJ. Fenton | Proposed Standard | November 2019 |
| 8494 | Multicast Email (MULE) over Allied Communications Publication (ACP) 142D. Wilson, A. Melnikov, Ed. | Informational | November 2018 |
| 8461 | SMTP MTA Strict Transport Security (MTA-STS)D. Margolis, M. Risher, B. Ramakrishnan, A. Brotman, J. Jones | Proposed Standard | September 2018 |
| 8460 | SMTP TLS ReportingD. Margolis, A. Brotman, B. Ramakrishnan, J. Jones, M. Risher | Proposed Standard | September 2018 |
| 8314 | Cleartext Considered Obsolete: Use of Transport Layer Security (TLS) for Email Submission and AccessK. Moore, C. Newman | Proposed Standard | January 2018 |
| 7817 | Updated Transport Layer Security (TLS) Server Identity Check Procedure for Email-Related ProtocolsA. Melnikov | Proposed Standard | March 2016 |
| 7672 | SMTP Security via Opportunistic DNS-Based Authentication of Named Entities (DANE) Transport Layer Security (TLS)V. Dukhovni, W. Hardaker | Proposed Standard | October 2015 |
| 7508 | Securing Header Fields with S/MIMEL. Cailleux, C. Bonatti | Experimental | April 2015 |
| 7435 | Opportunistic Security: Some Protection Most of the TimeV. Dukhovni | Informational | December 2014 |
| 7165 | Use Cases and Requirements for JSON Object Signing and Encryption (JOSE)R. Barnes | Informational | April 2014 |
| 6919 | Further Key Words for Use in RFCs to Indicate Requirement LevelsR. Barnes, S. Kent, E. Rescorla | Experimental | 1 April 2013 |
| 6758 | Tunneling of SMTP Message Transfer PrioritiesA. Melnikov, K. Carlberg | Informational | October 2012 |
| 6710 | Simple Mail Transfer Protocol Extension for Message Transfer PrioritiesA. Melnikov, K. Carlberg | Proposed Standard | August 2012 |
| 6531 | SMTP Extension for Internationalized EmailJ. Yao, W. Mao | Proposed Standard | February 2012 |
| 6409 | Message Submission for MailR. Gellens, J. Klensin | Internet Standard | November 2011 |
| 6394 | Use Cases and Requirements for DNS-Based Authentication of Named Entities (DANE)R. Barnes | Informational | October 2011 |
| 6186 | Use of SRV Records for Locating Email Submission/Access ServicesC. Daboo | Proposed Standard | March 2011 |
| 6125 | Representation and Verification of Domain-Based Application Service Identity within Internet Public Key Infrastructure Using X.509 (PKIX) Certificates in the Context of Transport Layer Security (TLS)P. Saint-Andre, J. Hodges · obsoleted by RFC 9525 | Proposed Standard | March 2011 |
| 6109 | La Posta Elettronica Certificata - Italian Certified Electronic MailC. Petrucci, F. Gennai, A. Shahin, A. Vinciarelli | Informational | April 2011 |
| 6047 | iCalendar Message-Based Interoperability Protocol (iMIP)A. Melnikov, Ed. | Proposed Standard | December 2010 |
| 5598 | Internet Mail ArchitectureD. Crocker | Informational | July 2009 |
| 5550 | The Internet Email to Support Diverse Service Environments (Lemonade) ProfileD. Cridland, Ed., A. Melnikov, Ed., S. Maes, Ed. | Proposed Standard | August 2009 |
| 5336 | SMTP Extension for Internationalized Email AddressesJ. Yao, Ed., W. Mao, Ed. · obsoleted by RFC 6531 | Experimental | September 2008 |
| 5068 | Email Submission Operations: Access and Accountability RequirementsC. Hutzler, D. Crocker, P. Resnick, E. Allman, T. Finch | Best Current Practice | November 2007 |
| 4954 | SMTP Service Extension for AuthenticationR. Siemborski, Ed., A. Melnikov, Ed. | Proposed Standard | July 2007 |
| 4786 | Operation of Anycast ServicesJ. Abley, K. Lindqvist | Best Current Practice | December 2006 |
| 4642 | Using Transport Layer Security (TLS) with Network News Transfer Protocol (NNTP)K. Murchison, J. Vinocur, C. Newman | Proposed Standard | October 2006 |
| 4550 | Internet Email to Support Diverse Service Environments (Lemonade) ProfileS. Maes, A. Melnikov · obsoleted by RFC 5550 | Proposed Standard | June 2006 |
| 4468 | Message Submission BURL ExtensionC. Newman | Proposed Standard | May 2006 |
| 4409 | Message Submission for MailR. Gellens, J. Klensin · obsoleted by RFC 6409 | Draft Standard | April 2006 |
| 4217 | Securing FTP with TLSP. Ford-Hutchinson | Proposed Standard | October 2005 |
| 3965 | A Simple Mode of Facsimile Using Internet MailK. Toyoda, H. Ohno, J. Murai, D. Wing | Draft Standard | December 2004 |
| 3887 | Message Tracking Query ProtocolT. Hansen | Proposed Standard | September 2004 |
| 3848 | ESMTP and LMTP Transmission Types RegistrationC. Newman | Draft Standard | July 2004 |
| 3792 | Survey of IPv4 Addresses in Currently Deployed IETF Security Area Standards Track and Experimental DocumentsP. Nesser, II, A. Bergstrom, Ed. | Informational | June 2004 |
| 3552 | Guidelines for Writing RFC Text on Security ConsiderationsE. Rescorla, B. Korver | Best Current Practice | July 2003 |
| 3436 | Transport Layer Security over Stream Control Transmission ProtocolA. Jungmaier, E. Rescorla, M. Tuexen | Proposed Standard | December 2002 |