| 8689 | SMTP Require TLS OptionJ. Fenton | Proposed Standard | November 2019 |
| 8621 | The JSON Meta Application Protocol (JMAP) for MailN. Jenkins, C. Newman | Proposed Standard | August 2019 |
| 8494 | Multicast Email (MULE) over Allied Communications Publication (ACP) 142D. Wilson, A. Melnikov, Ed. | Informational | November 2018 |
| 8098 | Message Disposition NotificationT. Hansen, Ed., A. Melnikov, Ed. | Internet Standard | February 2017 |
| 6857 | Post-Delivery Message Downgrading for Internationalized Email MessagesK. Fujiwara | Proposed Standard | March 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 |
| 6533 | Internationalized Delivery Status and Disposition NotificationsT. Hansen, Ed., C. Newman, A. Melnikov | Proposed Standard | February 2012 |
| 6531 | SMTP Extension for Internationalized EmailJ. Yao, W. Mao | Proposed Standard | February 2012 |
| 6530 | Overview and Framework for Internationalized EmailJ. Klensin, Y. Ko | Proposed Standard | February 2012 |
| 6522 | The Multipart/Report Media Type for the Reporting of Mail System Administrative MessagesM. Kucherawy, Ed. | Internet Standard | January 2012 |
| 6409 | Message Submission for MailR. Gellens, J. Klensin | Internet Standard | November 2011 |
| 6109 | La Posta Elettronica Certificata - Italian Certified Electronic MailC. Petrucci, F. Gennai, A. Shahin, A. Vinciarelli | Informational | April 2011 |
| 6009 | Sieve Email Filtering: Delivery Status Notifications and Deliver-By ExtensionsN. Freed | Proposed Standard | October 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 |
| 5504 | Downgrading Mechanism for Email Address InternationalizationK. Fujiwara, Ed., Y. Yoneya, Ed. · obsoleted by RFC 6530 | Experimental | March 2009 |
| 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 |
| 5321 | Simple Mail Transfer ProtocolJ. Klensin | Draft Standard | October 2008 |
| 5230 | Sieve Email Filtering: Vacation ExtensionT. Showalter, N. Freed, Ed. | Proposed Standard | January 2008 |
| 4954 | SMTP Service Extension for AuthenticationR. Siemborski, Ed., A. Melnikov, Ed. | Proposed Standard | July 2007 |
| 4952 | Overview and Framework for Internationalized EmailJ. Klensin, Y. Ko · obsoleted by RFC 6530 | Informational | July 2007 |
| 4865 | SMTP Submission Service Extension for Future Message ReleaseG. White, G. Vaudreuil | Proposed Standard | May 2007 |
| 4550 | Internet Email to Support Diverse Service Environments (Lemonade) ProfileS. Maes, A. Melnikov · obsoleted by RFC 5550 | Proposed Standard | June 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 |
| 4356 | Mapping Between the Multimedia Messaging Service (MMS) and Internet MailR. Gellens | Proposed Standard | January 2006 |
| 3888 | Message Tracking Model and RequirementsT. Hansen | Informational | September 2004 |
| 3886 | An Extensible Message Format for Message Tracking ResponsesE. Allman | Proposed Standard | September 2004 |
| 3885 | SMTP Service Extension for Message TrackingE. Allman, T. Hansen | Proposed Standard | September 2004 |
| 3834 | Recommendations for Automatic Responses to Electronic MailK. Moore | Proposed Standard | August 2004 |
| 3798 | Message Disposition NotificationT. Hansen, Ed., G. Vaudreuil, Ed. · obsoleted by RFC 8098 | Draft Standard | May 2004 |
| 3795 | Survey of IPv4 Addresses in Currently Deployed IETF Application Area Standards Track and Experimental DocumentsR. Sofia, P. Nesser, II | Informational | June 2004 |
| 3482 | Number Portability in the Global Switched Telephone Network (GSTN): An OverviewM. Foster, T. McGarry, J. Yu | Informational | February 2003 |
| 3464 | An Extensible Message Format for Delivery Status NotificationsK. Moore, G. Vaudreuil | Draft Standard | January 2003 |
| 3462 | The Multipart/Report Content Type for the Reporting of Mail System Administrative MessagesG. Vaudreuil · obsoleted by RFC 6522 | Draft Standard | January 2003 |
| 3459 | Critical Content Multi-purpose Internet Mail Extensions (MIME) ParameterE. Burger | Proposed Standard | January 2003 |