1971

MAIL
MAILRFCs
RFCs

1972
RFC 171
The Data
TransferProtocolRFC 172
The File
TransferProtocol1973

RFC 264
The Data
TransferProtocolRFC 265
The File
TransferProtocolRFC 141
Comments on RFC 114:
A File Transfer Protocol
RFC 196 RFC 278
Mail Box Revision of theProtocol Mail Box Protocol

HISTORICHISTORIC

82 84 86 88 90 91

1992

1993

1994

RFC 469
Networkmailmeetingsummary

RFC 221
Mail Box Protocol:
Version 2

1995

1996

1977

1978

1979

1981

RFC 720
Address
Specification
Syntax for
Network Mail

1999

1982

1983

2001

1985

RFC 753
Internet Message
ProtocolRFC 772
Mail Transfer
ProtocolRFC 754
Out-of-net hostaddresses for
mail

RFC 771
Mail transition
plan

RFC 780
Mail
TransferProtocolRFC 788
Simple Mail
Transfer Protocol

RFC 821 / STD 10
Simple Mail Transfer
ProtocolRFC 876
Survey of SMTP
implementations

2004

POP
POP

2005

2006

RFC 886
Proposedstandard formessage header
munging

2007

RFC 937 / Historic
Post Office Protocol:
Version 2

2010

RFC 1047
Duplicate messages and
SMTP

RFC 1090
SMTP on X.25

RFC 1123 / STD 3
Requirements for Internet
Hosts -- Application andSupport

RFC 1426 / PS
SMTP Service Extension for
8bit-MIMEtransport

RFC 1652 / DS
SMTP Service Extension for
8bit-MIMEtransport

RFC 1427 / PS
SMTP Service Extension for
Message Size Declaration

RFC 1653 / DS
SMTP Service Extension for
Message Size Declaration

RFC 1870 / STD 10
SMTP Service Extension for
Message Size Declaration

RFC 3207 / PS
SMTP Service Extension for
Secure SMTP overTransport Layer Security

RFC 2487 / PS
SMTP Service Extension for
Secure SMTP over TLS

RFC 1854 / PS
SMTP Service Extension for
Command Pipelining

RFC 2197 / DS
SMTP Service Extension for
Command Pipelining

RFC 4865 / PS
SMTP Submission Service
Extension for Future
Message Release

RFC 8098 / STD 85
Message Disposition
Notification

RFC 5248 / BCP 138
A Registry for SMTP
Enhanced Mail System
Status Codes

RFC 3462 / DS
The Multipart/Report
Content Type for theReporting of Mail System
Administrative Messages

RFC 5337 / Experimental
Internationalized Delivery
Status and Disposition
Notifications

RFC 6533 / PS
Internationalized Delivery
Status and Disposition
Notifications

RFC 1893 / PS
Enhanced Mail System
Status Codes

RFC 3463 / DS
Enhanced Mail System
Status Codes

RFC 5336 / Experimental
SMTP Extension forInternationalized Email
Addresses

RFC 6531 / PS
SMTP Extension forInternationalized EmailRFC 2852 / PS
Deliver By SMTP Service
Extension

RFC 3885 / PS
SMTP Service Extension for
Message Tracking

RFC 3464 / DS
An Extensible Message
Format for Delivery Status
Notifications

RFC 3886 / PS
An Extensible Message
Format for Message
Tracking Responses

RFC 1731 / PS
IMAP4 Authentication
Mechanisms
RFC 1732 / Informational
IMAP4 Compatibility with
IMAP2 and IMAP2bis

RFC 3656 / Experimental
The Mailbox Update(MUPDATE) Distributed
Mailbox Database Protocol

RFC 2060 / PS
Internet Message AccessProtocol - Version 4rev1

RFC 3501 / PS
Internet Message AccessProtocol - Version 4rev1

RFC 2061 / Informational
IMAP4 Compatibility with
IMAP2bis

RFC 3502 / PS
Internet Message AccessProtocol (IMAP) MULTIAPPEND Extension

RFC 2683 / Informational
IMAP4 Implementation
Recommendations

RFC 2342 / PS
IMAP4 Namespace

RFC 2359 / PS
IMAP4 UIDPLUS extension

RFC 3348 / Informational
The Internet Message Action
Protocol (IMAP4) Child
Mailbox Extension

RFC 2088 / PS
IMAP4 non-synchronizing
literals

RFC 6858 / PS
Simplified POP and IMAP
Downgrading forInternationalized EmailRFC 5738 / Experimental
IMAP Support for UTF-8
RFC 4959 / PS
IMAP Extension for Simple
Authentication and Security Layer(SASL) Initial Client Response

RFC 4314 / PS
IMAP4 Access Control List
(ACL) Extension

RFC 3516 / PS
IMAP4 Binary Content
Extension

RFC 2971 / PS
IMAP4 ID extension

RFC 6857 / PS
Post-Delivery Message
Downgrading forInternationalized Email
Messages

RFC 6186 / PS
Use of SRV Records for
Locating Email
Submission/Access Services

RFC 4146 / Informational
Simple New Mail Notification

RFC 3503 / PS
Message Disposition
Notification (MDN) profile forInternet Message AccessProtocol (IMAP)

RFC 2087 / PS
IMAP4 QUOTA extension

RFC 3691 / PS
Internet Message AccessProtocol (IMAP) UNSELECT
command

RFC 6855 / PS
IMAP Support for UTF-8

RFC 5530 / PS
IMAP Response
Codes
RFC 5788 / PS
IMAP4 Keyword Registry

RFC 4978 / PS
The IMAP
COMPRESS Extension

RFC 5259 / PS
Internet Message AccessProtocol - CONVERTExtension

RFC 5032 / PS
WITHIN Search
Extension to the IMAP
ProtocolRFC 5267 / PS
Contexts for IMAP4

RFC 4315 / PS
Internet Message AccessProtocol (IMAP) - UIDPLUS
extension

RFC 5161 / PS
The IMAP ENABLE
Extension

RFC 5464 / PS
The IMAP METADATA
Extension

RFC 5162 / PS
RFC 5465 / PS
IMAP4 Extensions for
The IMAP NOTIFY
Quick Mailbox
Extension
Resynchronization
RFC 4467 / PS
RFC 5182 / PS
RFC 5466 / PS
Internet Message Access
IMAP Extension for
IMAP4 Extension for Named
Protocol (IMAP) - URLAUTH
Referencing the Last
Searches (Filters)
Extension
SEARCH Result
RFC 6154 / PS
IMAP LIST Extension for
RFC 4469 / PS
RFC 5255 / PS
Special-Use Mailboxes
Internet Message AccessInternet Message AccessProtocol (IMAP) CATENATE
ProtocolExtension
Internationalization
RFC 6203 / PS
IMAP4 Extension for Fuzzy
RFC 4551 / PS
RFC 5256 / PS
RFC 5593 / PS
SearchIMAP Extension for Conditional
Internet Message AccessInternet Message Access
STORE Operation or Quick Flag
Protocol - SORT and
Protocol (IMAP) - URL
Changes Resynchronization
THREAD Extensions
Access Identifier Extension
RFC 6237 / PS
IMAP4 Multimailbox
RFC 4731 / PS
RFC 5257 / Experimental
RFC 5819 / PS
IMAP4 Extension to SEARCHInternet Message Access
IMAP4 Extension for Returning SEARCH Extension
Command for Controlling What
Protocol - ANNOTATESTATUS Information in
Kind of Information Is Returned
Extension
Extended LIST
RFC 5258 / PS
RFC 5957 / PS
RFC 4549 / Informational
RFC 5092 / PS
Internet
MessageAccess
Display-Based Address
Synchronization Operations
IMAP URL
Protocolversion4
LIST
Sorting for the IMAP4 SORT
for Disconnected IMAP4
SchemeCommand Extensions
Extension
Clients
RFC 4466 / PS
Collected Extensions to
IMAP4 ABNF

RFC 2177 / PS
IMAP4 IDLE command
RFC 2180 / Informational
IMAP4 Multi-Accessed
Mailbox PracticeRFC 2192 / PS
IMAP URL Scheme
RFC 2193 / PS
IMAP4 Mailbox Referrals

IMAP/POP3
IMAP/POP3

RFC 6856 / PS
Post Office Protocol Version
3 (POP3) Support for UTF-8

RFC 5721 / PS
POP3 Support for UTF-8

RFC 4616 / PS
The PLAIN Simple
Authentication and Security
Layer (SASL) Mechanism

RFC 2595 / PS
Using TLS with IMAP, POP3
and ACAP

RFC 2086 / PS
IMAP4 ACL extension

RFC 6783 / Informational
Mailing Lists and Non-ASCII
Addresses

RFC 3206 / PS
The SYS and AUTH POP
Response Codes

RFC 2384 / PS
POP URL Scheme

RFC 2062 / Informational
Internet Message AccessProtocol - Obsolete Syntax

RFC 1733 / Informational
Distributed Electronic Mail
Models in IMAP4DSN,
DSN,MDN
MDN

RFC 6530 / PS
Overview and Framework
for Internationalized EmailRFC 5983 / Experimental
Mailing Lists andInternationalized Email
Addresses

RFC 5034 / PS
The Post Office Protocol(POP3) Simple Authenticationand Security Layer (SASL)
Authentication Mechanism

RFC 2195 / PS
IMAP/POP AUTHorize
Extension for Simple
Challenge/Response

RFC 1730 / PS
Internet Message AccessProtocol - Version 4

RFC 5825 / Experimental
Displaying Downgraded
Messages for Email
Address Internationalization

RFC 5504 / Experimental
Downgrading Mechanism
for Email Address
Internationalization

EAI
EAI
RFC 2449 / PS
POP3 Extension
Mechanism

POP3
POP3

RFC 6522 / STD 73
The Multipart/Report MediaType for the Reporting ofMail System Administrative
Messages

RFC 4952 / Informational
Overview and Framework
for Internationalized EmailRFC 2033 / Informational
Local Mail Transfer Protocol

IMAP/POP3
IMAP/POP3

RFC 7505 / PS
A "Null MX" No Service
Resource Record for
Domains That Accept No
Mail

Message
MessageSubmission,
Submission,SMTP-AUTH
SMTP-AUTH

RFC 3798 / DS
Message Disposition
Notification

RFC 2095 / PS
IMAP/POP AUTHorize
Extension for Simple
Challenge/Response

RFC 6710 / PS
Simple Mail Transfer
Protocol Extension for
Message Transfer Priorities

RFC 7817 / PS
Updated Transport Layer
Security (TLS) Server
Identity Check Procedurefor Email-Related Protocols

RFC 1892 / PS
The Multipart/Report
Content Type for theReporting of Mail System
Administrative Messages

RFC 1957 / Informational
Some Observations on
Implementations of the Post
Office Protocol (POP3)

RFC 7504 / PS
SMTP 521 and 556 Reply
Codes

RFC 7672 / PS
SMTP Security via Opportunistic
DNS-Based Authentication ofNamed Entities (DANE) Transport
Layer Security (TLS)

RFC 3461 / DS
Simple Mail Transfer
Protocol (SMTP) Service
Extension for Delivery
Status Notifications (DSNs)

RFC 1734 / PS
POP3 AUTHenticationcommand

RFC 6729 / PS
Indicating Email HandlingStates in Trace Fields

RFC 6409 / STD 70
Message Submission for
Mail

RFC 4468 / PS
Message Submission
BURL Extension

RFC 2298 / PS
An Extensible Message
Format for Message
Disposition Notifications

RFC 1939 / STD 53
Post Office Protocol Version 3

2017

RFC 7293 / PS
The Require-RecipientValid-Since Header Field
and SMTP Service
Extension

RFC 1891 / PS
SMTP Service Extension for
Delivery Status Notifications

RFC 1725 / STD 53
Post Office Protocol Version 3

2016

RFC 4954 / PS
SMTP Service Extension for
Authentication

RFC 2645 / PS
ON-DEMAND MAIL RELAY(ODMR) SMTP with
Dynamic IP Addresses

RFC 1711 / Informational
Classifications in E-mailRouting

2015

RFC 1339 / Experimental
Remote Mail Checking
ProtocolRFC 7103 / Informational
Advice for Safe Handling ofMalformed Messages

RFC 4409 / DS
Message Submission for
Mail

RFC 1894 / PS
An Extensible Message
Format for Delivery Status
Notifications

RFC 1082
Post Office Protocol:
Version 3: Extended service
offerings

2014

RFC 1204 / Experimental
Message Posting
Protocol (MPP)

RFC 5068 / BCP 134
Email Submission
Operations: Access andAccountability Requirements

RFC 2554 / PS
SMTP Service Extension for
Authentication

RFC 2034 / PS
SMTP Service Extension for
Returning Enhanced Error
Codes

RFC 1225 / DS
Post Office Protocol:
Version 3

2013

RFC 3974 / Informational
SMTP Operational
Experience in Mixed IPv4/v6
Environments

RFC 2476 / PS
Message Submission

RFC 1846 / Experimental
SMTP 521 Reply Code

PEM
PEM

RFC 1203 / HistoricInteractive Mail AccessProtocol: Version 3
RFC 1137 / Historic
Mapping between full
RFC 822 and RFC 822
with restricted encoding.

RFC 4141 / PS
SMTP and MIME
Extensions for Content
Conversion

RFC 3030 / PS
SMTP Service Extensions
for Transmission of Largeand Binary MIME Messages

RFC 1845 / Experimental
SMTP Service Extension for
Checkpoint/Restart

RFC 1460 / DS
Post Office Protocol Version 3

RFC 3848 / DS
ESMTP and LMTP
Transmission Types
Registration

RFC 2920 / STD 60
SMTP Service Extension for
Command Pipelining

RFC 1985 / PS
SMTP Service Extension for
Remote Message Queue
Starting

RFC 1421 / Historic
Privacy Enhancement forInternet Electronic Mail: Part
I: Message Encryption andAuthentication Procedures
RFC 1422 / Historic
Privacy Enhancement forInternet Electronic Mail: Part
II: Certificate-Based Key
Management
RFC 1423 / Historic
Privacy Enhancement forInternet Electronic Mail: Part
III: Algorithms, Modes, andIdentifiers
RFC 1424 / Historic
Privacy Enhancement forInternet Electronic Mail: Part
IV: Key Certification and
Related Services

RFC 4405 / Experimental
SMTP Service Extension for
Indicating the Responsible
Submitter of an E-Mail
Message

RFC 3865 / PS
A No Soliciting Simple Mail
Transfer Protocol (SMTP)
Service Extension

RFC 1830 / Experimental
SMTP Service Extensions
for Transmission of Largeand Binary MIME Messages

RFC 1081
Post Office Protocol:
Version 3

RFC 1064
Interactive Mail AccessProtocol: Version 2

2012

1993

RFC 1176 / Experimental
Interactive Mail AccessProtocol: Version 2

IMAP
IMAP

RFC 6152 / STD 71
SMTP Service Extension for
8-bit MIME Transport

RFC 1428 / Informational
Transition of Internet Mailfrom Just-Send-8 to 8bitSMTP/MIME

SMTP
SMTP

RFC 1056 / Informational
PCMAIL: A Distributed
Mail System for Personal
Computers

2011

1992

RFC 5321 / DS
Simple Mail Transfer
ProtocolRFC 2505 / BCP 30
Anti-Spam
Recommendations for
SMTP MTAs

RFC 1869 / STD 10
SMTP Service Extensions

1991

RFC 1113 / Historic
Privacy enhancement forInternet electronic mail: Part I message encipherment andauthentication procedures
RFC 1114 / Historic
Privacy enhancement forInternet electronic mail: Part II- certificate-based key
management
RFC 1115 / Historic
Privacy enhancement forInternet electronic mail: Part III- algorithms, modes, andidentifiers

RFC 976
UUCP mail interchange
format standard

2009

RFC 2821 / PS
Simple Mail Transfer
ProtocolRFC 1651 / DS
SMTP Service Extensions

1990

RFC 5598 / Informational
Internet Mail Architecture

RFC 821 / STD 10
Simple Mail Transfer
ProtocolRFC 1425 / PS
SMTP Service Extensions

RFC 993PCMAIL: A Distributed
Mail System for Personal
Computers

RFC 984
PCMAIL: A Distributed
Mail System for Personal
Computers

RFC 915
Network mail pathservice

2008

1989

RFC 989 / Historic
Privacy enhancement forInternet electronic mail: Part I:
Message encipherment andauthentication procedures

PCMAILPCMAILRFC 2142 / PS
Mailbox Names for
Common Services, Rolesand Functions

RFC 974 / STD 10, Historic
Mail routing and the domain
system1988

RFC 1040 / Historic
Privacy enhancement forInternet electronic mail: Part I:
Message encipherment andauthentication procedures

RFC 918
Post Office Protocol

RFC 822 / STD 11
STANDARD FOR THE
FORMAT OF ARPA
INTERNET TEXTMESSAGES

2003

1987

MTP,
MTP,SMTPSMTP

RFC 773
Comments on
NCP/TCP mail service
transition strategy
RFC 767
Structured format fortransmission of multimedia documents

2002

1986

RFC 959 / STD 9File Transfer Protocol

RFC 733
Standard for the format
of ARPA network text
messages

2000

1984

RFC 765
File Transfer
ProtocolRFC 724
Proposed official
standard for the format
of ARPA Network
messages

Message
MessageFormat
Format
RFC 680
MessageTransmission
Protocol

1998

1980

RFC 751
Survey of FTP
mail and MLFL

RFC 706
On the junk mailproblem

RFC 561
Standardizing
Network Mail
Headers

1997

RFC 1168 / Informational
Intermail and Commercial
Mail Relay services

Misc.
Misc.

1976

FTP
FTPmailmail

RFC 133
File Transfer andError Recovery

Edition: 2017-07-02
To view the latest edition, visit http://emaillab.jp/mail/mail-rfc/.

1975

RFC 354
RFC 542
File
File
Transfer RFC 414
Transfer
RFC 614
Protocol File Transfer
ProtocolResponse to RFC 607:
Protocol (FTP)"Comments on the Filestatus and further RFC 524
Transfer Protocol"
Proposed Mail
comments
ProtocolRFC 640
RFC 385
RFC 454
Revised FTP
RFC 539
Comments
File Transfer Protocol
reply codes
Thoughts on the mailon the Filemeeting announcement
protocol proposed inTransfer
and a new proposed
RFC 630
RFC 524
Protocoldocument
FTP error code
RFC 555
usage for more
RFC 458
Responses to critiquesreliable mail service
Mail retrievalof the proposed mailvia FTP
protocolRFC 475
RFC 644
FTP and
RFC 577
On the problem of
Network Mail
Mail priority
signature authentication
Systemfor network mailRFC 114File Transfer
Protocol(c) 2014-2017 by Takashi Takizawa
This diagram is licensed under the Creative Commons
Attribution 4.0 International License. To view a copy of thislicense, visit http://creativecommons.org/licenses/by/4.0/.

1974

RFC 2221 / PS
IMAP4 Login Referrals

RFC 7888 / PS
MAP4 Non-synchronizing
Literals
RFC 7162 / PS
IMAP Extensions: Quick Flag
Changes Resynchronization(CONDSTORE) and Quick Mailbox
Resynchronization (QRESYNC)

RFC 6851 / PS
Internet Message AccessProtocol (IMAP) - MOVE
Extension

RFC 7889 / PS
The IMAP APPENDLIMIT
Extension

RFC 7377 / PS
IMAP4 Multimailbox
SEARCH Extension

IMAP
IMAP
RFC 5442 / Informational
LEMONADE Architecture - Supporting
Open Mobile Alliance (OMA) Mobile Email(MEM) Using Internet Mail
RFC 5383 / BCP 143
Deployment
Considerations forLemonade-Compliant
Mobile Email

Lemonade
Lemonade
RFC 4550 / PS
Internet Email to Support
Diverse Service
Environments (Lemonade)ProfileRFC 987 / Unknown
Mapping between
X.400 and RFC 822
RFC 1026 / Unknown
Addendum to RFC
987: (Mapping
between X.400 and
RFC-822)
RFC 1138 /Experimental
Mapping between
X.400(1988) / ISO10021 and RFC 822

RFC 2156 / PS
MIXER (Mime Internet
X.400 Enhanced Relay):
Mapping between X.400
and RFC 822/MIMEs

RFC 1327 / PS
Mapping between
X.400(1988) / ISO 10021
and RFC 822

RFC 1495 / PS
Mapping between X.400
and RFC-822 Message
Bodies

RFC 1328 / Historic
X.400 1988 to 1984
downgrading

RFC 1496 / Historic
Rules for downgrading messages
from X.400/88 to X.400/84 when
MIME content-types are present
in the messages

RFC 2157 / PS
Mapping between X.400
and RFC-822/MIME
Message Bodies

RFC 1405 / Experimental
Mapping between
X.400(1984/1988) and Mail11 (DECnet mail)RFC 1506 / Informational
A Tutorial on Gatewaying
between X.400 andInternet Mail

MIXER
MIXER

RFC 3431 / PS
Sieve Extension: Relational
Tests
RFC 3894 / PS
Sieve Extension: Copying
Without Side Effects

RFC 2162 / Experimental
MaXIM-11 - Mapping
between X.400 / Internet
mail and Mail-11 mailRFC 1494 / Historic
Equivalences between
1988 X.400 and RFC-822
Message Bodies

RFC 1649 / Informational
Operational Requirements
for X.400 Management
Domains in the GO-MHS
Community

RFC 3598 / PS
Sieve Email Filtering -Subaddress Extension

RFC 2163 / PS
Using the Internet DNS toDistribute MIXER
Conformant Global Address
Mapping (MCGAM)

RFC 1664 / Experimental
Using the Internet DNS toDistribute RFC1327 Mail
Address Mapping Tables

mailtomailtoURI
URI

RFC 1838 / Experimental
Use of the X.500 Directory tosupport mapping between
X.400 and RFC 822
Addresses

RFC 3685 / PS
SIEVE Email Filtering: Spamtest
and VirusTest Extensions

Sieve
Sieve

RFC 2164 / PS
Use of an X.500/LDAP
directory to support MIXER
address mapping

RFC 1738 / PS
Uniform Resource Locators(URL)

RFC 2368 / PS
The mailto URL scheme

RFC 2369 / PS
The Use of URLs as Meta-Syntax
for Core Mail List Commands andtheir Transport through Message
Header Fields

RFC 2076 / Informational
Common Internet Message
Headers

Message
MessageFormat
Format

RFC 2919 / PS
List-Id: A Structured Field
and Namespace for the
Identification of Mailing Lists

RFC 3864 / BCP 90
Registration Procedures for
Message Header Fields

RFC 5335 / Experimental
Internationalized Email
Headers

RFC 2822 / PS
Internet Message Format

RFC 1154 / Experimental
Encoding header field forinternet messages

RFC 1505 / Experimental
Encoding Header Field forInternet Messages
RFC 1521 / DS
MIME (Multipurpose Internet Mail
Extensions) Part One: Mechanisms
for Specifying and Describing theFormat of Internet Message Bodies

RFC 2045 / DS
Multipurpose Internet Mail
Extensions (MIME) Part
One: Format of Internet
Message Bodies

RFC 1342 / PS
Representation of NonASCII Text in Internet
Message Headers

RFC 1522 / DS
MIME (Multipurpose Internet
Mail Extensions) Part Two:
Message Header Extensions
for Non-ASCII Text

RFC 2046 / DS
Multipurpose Internet Mail
Extensions (MIME) Part
Two: Media Types

RFC 1343 / Informational
A User Agent Configuration
Mechanism for Multimedia
Mail Format Information

RFC 1524 / Informational
A User Agent Configuration
Mechanism For Multimedia
Mail Format Information

RFC 2047 / DS
MIME (Multipurpose Internet
Mail Extensions) Part Three:
Message Header Extensions
for Non-ASCII Text

RFC 1344 / Informational
Implications of MIME forInternet Mail Gateways

RFC 1544 / PS
The Content-MD5 Header
Field

RFC 2049 / DS
Multipurpose Internet
Mail Extensions (MIME)Part Five: Conformance
Criteria and Examples

RFC 1864 / DS
The Content-MD5
Header Field
RFC 1806 / Experimental
Communicating
Presentation Information inInternet Messages: The
Content-Disposition Header

UnknownStandard

RFC 1523 / Informational
The text/enriched MIME
Content-type

Best Current
Practice

RFC 6477 / Informational
Registration of Military
Message Handling System(MMHS) Header Fields for
Use in Internet Mails

RFC 7912 / Informational
Message Authorizing Email
Header Field and Its Use forthe Draft and Release
Procedure

RFC 4249 / Informational
Implementer-FriendlySpecification of Message andMIME-Part Header Fields andField Components

RFC 3676 / PS
The Text/Plain Format andDelSp Parameters

RFC 2789 / BCP 19
IANA Charset Registration
Procedures

RFC 4288 / BCP 13
Media Type Specifications
and Registration Procedures

RFC 6838 / BCP 13
Media Type Specifications
and Registration Procedures
RFC 6657 / PS
Update to MIME regarding"charset" Parameter
Handling in Textual MediaTypes

RFC 2231 / PS
MIME Parameter Value andEncoded Word Extensions:Character Sets, Languages,
and Continuations

RFC 5147 / PS
URI Fragment Identifiers forthe text/plain Media TypeRFC 2183 / PS
Communicating Presentation
Information in Internet
Messages: The ContentDisposition Header Field

RFC 7444 / PS
Security Labels in Internet
Email

RFC 6839 / Informational
Additional Media Type
Structured Syntax Suffixes

RFC 3023 / PS
XML Media Types

RFC 7303 / PS
XML Media Types

RFC 2110 / PS
MIME E-mail Encapsulationof Aggregate Documents,
such as HTML (MHTML)RFC 1844 / Informational
Multimedia E-mail (MIME)
User Agent Checklist

RFC 2111 / PS
Content-ID and Message-ID
Uniform Resource Locators

RFC 2392 / PS
Content-ID and Message-ID
Uniform Resource Locators

RFC 2112 / PS
The MIME Multipart/Related
Content-type

RFC 2387 / PS
The MIME
Multipart/Related
Content-type

RFC 7072 / PS
A Reputation Query Protocol

RFC 2376 / Informational
XML Media Types

RFC 7073 / PS
A Reputation Response Set
for Email Identifiers

RFC 1872 / Experimental
The MIME Multipart/Related
Content-type

RFC 1740 / PS
MIME Encapsulation ofMacintosh Files MacMIME
RFC 1741 / Informational
MIME Content Type for
BinHex Encoded Files

MIME
MIME

RFC 6648 / BCP 178
Deprecating the "X-" Prefix
and Similar Constructs in
Application Protocols

RFC 5064 / PS
The Archived-At Message
Header Field

RFC 4289 / BCP 13
Multipurpose Internet Mail
Extensions (MIME) Part
Four: Registration
Procedures
RFC 2184 / PS
MIME Parameter Value andEncoded Word Extensions:Character Sets, Languages,
and Continuations

RFC 8058 / PS
Signaling One-Click
Functionality for List Email
Headers

RFC 1820 / Informational
Multimedia E-mail (MIME)
User Agent Checklist

RFC 1563 /Informational
The text/enriched
MIME Content-type

ProposedStandard

RFC 2646 / PS
The Text/Plain Format
Parameter

RFC 2278 / PS
IANA Charset Registration
Procedures

EAI
EAI
RFC 6854 / PS
Update to Internet Message
Format to Allow Group
Syntax in the "From:" and"Sender:" Header Fields

RFC 4096 / Informational
Policy-Mandated Labels Suchas "Adv:" in Email Subject
Headers Considered
Ineffective At BestRFC 2048 / BCP 13
Multipurpose Internet Mail
Extensions (MIME) Part
Four: Registration
Procedures

RFC 1590 / Informational
Media Type Registration
Procedure

Draft
Standard

RFC 4021 / PS
Registration of Mail and
MIME Header Fields

RFC 3282 / DS
Content Language Headers

RFC 1341 / PS
MIME (Multipurpose Internet Mail
Extensions): Mechanisms forSpecifying and Describing theFormat of Internet Message Bodies

RFC 6532 / PS
Internationalized Email
Headers

RFC 5322 / DSInternet Message Format

RFC 1766 / PS
Tags for the Identification of
Languages

RFC 7352 / PS
Sieve Email Filtering:
Detecting Duplicate
Deliveries

RFC 6196 / PS
Moving mailserver: URI
Scheme to Historic

RFC 6068 / PS
The 'mailto' URI Scheme

RFC 822 / STD 11
STANDARD FOR THE
FORMAT OF ARPA
INTERNET TEXTMESSAGES
RFC 934
Proposed Standard
for Message
Encapsulation

RFC 5784 / PS
RFC 5183 / PS
Sieve Email Filtering:
Sieve Email Filtering:
Sieves and Display
Environment Extension RFC 5435 / PS
RFC 6131 / PS
Directives in XML
Sieve Email Filtering:
Sieve Vacation Extension:
RFC 5229 / PS
Extension for Notifications"Seconds" Parameter
Sieve Email Filtering:
RFC 5436 / PS
RFC 6132 / PS
Variables Extension
Sieve Notification
Sieve Notification Using
RFC 5230 / PS
Mechanism: mailto
Presence Information
Sieve Email Filtering:
RFC 5437 / PS
RFC 6133 / Informational
Vacation Extension
Sieve Notification
Sieve Email Filtering: Use of
RFC 5231 / PS
Mechanism: Extensible
Presence Information withSieve Email Filtering:
Messaging and PresenceAuto-Responder
Relational Extension
Protocol (XMPP)Functionality
RFC 5232 / PS
RFC 5463 / PS
RFC 6134 / PS
Sieve Email Filtering:
Sieve Email Filtering: Ihave
Sieve Extension: ExternallyImap4flags Extension
Extension
Stored Lists
RFC
5490
/
PS
RFC 5233 / PS
RFC 6468 / PS
The Sieve Mail-Filtering
Sieve Email Filtering:
Sieve Notification
Language -- Extensions for
Subaddress Extension
Mechanism: SIP MESSAGE
Checking Mailbox Status and
RFC 5235 / PS
RFC 6558 / PS
Accessing Mailbox Metadata
Sieve Email Filtering: Spamtest
Sieve Extension for Convertingand Virustest Extensions
Messages before Delivery
RFC 5703 / PS
RFC 5260 / PS
RFC 6609 / PS
RFC 6009 / PS
Sieve
Email
Filtering:
MIME
Sieve Email Filtering: Date
Sieve Email Filtering:
Sieve Email Filtering:
Part Tests, Iteration,and Index Extensions
Include Extension
Delivery Status Notifications
Extraction, Replacement,
and Deliver-By Extensions
RFC 5293 / PS
and Enclosure
Sieve Email Filtering:
Editheader Extension

RFC 2160 / PS
Carrying PostScript in X.400
and MIME
RFC 2161 / Experimental
A MIME Body Part for ODA

RFC 6785 / PS
Support for Internet
Message Access Protocol(IMAP) Events in Sieve

RFC 5804 / PS
A Protocol for RemotelyManaging Sieve Scripts

RFC 5429 / PS
Sieve Email Filtering: Rejectand Extended Reject
Extensions

RFC 5173 / PS
Sieve Email Filtering:
Body Extension

RFC 3834 / PS
Recommendations for
Automatic Responses toElectronic Mail

RFC 2158 / PS
X.400 Image Body Parts

RFC 1648 / Historic
Postmaster Convention forX.400 Operations

RFC 5550 / PS
The Internet Email to
Support Diverse Service
Environments (Lemonade)ProfileRFC 5228 / PS
Sieve: An Email Filtering
Language

RFC 2159 / PS
A MIME Body Part for FAX

RFC 1148 /Experimental
Mapping between
X.400(1988) / ISO10021 and RFC 822

RFC 1049 / HistoricContent-type header fieldfor Internet messages

RFC 3028 / PS
Sieve: A Mail Filtering
Language

RFC 5551 / Informational
Lemonade Notifications
Architecture

RFC 1896 /Informational
The text/enriched
MIME Content-type
RFC 1873 /Experimental
Message/ExternalBody Content-ID
Access TypeRFC 2557 / PS
MIME Encapsulation ofAggregate Documents, suchas HTML (MHTML)RFC 2077 / PS
The Model Primary Content
Type for Multipurpose
Internet Mail Extensions

RFC 2017 / PS
Definition of the URL MIME
External-Body Access-Type

RFC 6471 / Informational
Overview of Best EmailDNS-Based List (DNSBL)
Operational Practices

RFC 5782 / Informational
DNS Blacklists andWhitelists

DNSBL
DNSBL

RFC 7070 / PS
An Architecture for
Reputation Reporting

RFC 6647 / PS
Email Greylisting: An
Applicability Statement for
SMTP

Greylisting
Greylisting

RFC 2442 / Informational
The Batch SMTP MediaType

RFC 7071 / PS
A Media Type for Reputation
Interchange

Reputation
Reputation

RFC 6650 / PS
Creation and Use of Email Feedback
Reports: An Applicability Statement for
the Abuse Reporting Format (ARF)

RFC 5965 / PS
An Extensible Format for
Email Feedback Reports

Informational
RFC 2303 / PS
Minimal PSTN addressformat in Internet Mail

RFC 3191 / DS
Minimal GSTN addressformat in Internet Mail

RFC 2304 / PS
Minimal FAX address format
in Internet Mail

RFC 3192 / DS
Minimal FAX addressformat in Internet Mail

RFC 3773 / Informational
High-Level Requirements
for Internet Voice Mail

Experimental

RFC 3249 / Informational
Implementers Guide for
Facsimile Using Internet
Mail

RFC 4142 / PS
Full-mode Fax Profile forInternet Mail (FFPIM)

RFC 6651 / PS
Extensions to DomainKeys Identified
Mail (DKIM) for Failure Reporting

RFC 4143 / PS
Facsimile Using Internet
Mail (IFAX) Service ofENUM

RFC 6652 / PS
Sender Policy Framework (SPF)
Authentication Failure Reporting Using
the Abuse Reporting Format

Historic

RFC 6590 / PS
Redaction of Potentially
Sensitive Data from Mail
Abuse Reports

RFC 3965 / DS
A Simple Mode of Facsimile
Using Internet Mail

RFC 2305 / PS
A Simple Mode of Facsimile
Using Internet Mail

Obsolete

FAX
FAXforforInternet
InternetMail
Mail

RFC 2846 / PS
GSTN Address Element
Extensions in E-mailServices

RFC 2532 / PS
Extended Facsimile Using
Internet Mail

UpdateRFC 1911 / Experimental
Voice Profile for Internet
Mail

Obsolete

RFC 3297 / PS
Content Negotiation for
Messaging Services basedon Email

RFC 3801 / DS
Voice Profile for Internet
Mail - version 2 (VPIMv2)

RFC 2422 / PS
Toll Quality Voice - 32 kbit/s
ADPCM MIME Sub-type
Registration

RFC 3802 / DS
Toll Quality Voice - 32 kbit/s
Adaptive Differential Pulse
Code Modulation (ADPCM)MIME Sub-type Registration

RFC 2423 / PS
VPIM Voice Message MIME
Sub-type Registration

RFC 3803 / PS
Content Duration MIMEHeader Definition

RFC 4405 / Experimental
SMTP Service Extension for
Indicating the Responsible
Submitter of an E-Mail
Message

RFC 2424 / PS
Content Duration MIMEHeader Definition

RFC 3804 / PS
Voice Profile for Internet
Mail (VPIM) Addressing

RFC 4406 / Experimental
Sender ID: Authenticating EMail

Voice
VoiceProfile
Profilefor
forInternet
InternetMail
Mail

RFC 1991 / Informational
PGP Message Exchange
Formats

RFC 5617 / PS
DomainKeys Identified Mail
(DKIM) Author Domain
Signing Practices (ADSP)RFC 4871 / Informational
DomainKeys Identified Mail
(DKIM) Signatures

RFC 5672 / Informational
DomainKeys Identified Mail
(DKIM) Signatures -- Update

RFC 2313 / Informational
PKCS #1: RSA Encryption
Version 1.5

RFC 2634 / PS
Enhanced Security Services
for S/MIME

RFC 3447 / Informational
Public-Key CryptographyStandards (PKCS) #1: RSA
Cryptography Specifications
Version 2.1

RFC 3369 / PS
Cryptographic Message
Syntax (CMS)

RFC 3852 / PS
Cryptographic Message
Syntax (CMS)

1999

2000

2001

RFC 3854 / PS
Securing X.400 Content
with Secure/Multipurpose
Internet Mail Extensions(S/MIME)

RFC 3114 / Informational
Implementing Company
Classification Policy with the
S/MIME Security Label

2002

RFC 5083 / PS
Cryptographic Message
Syntax (CMS)
Authenticated-EnvelopedData Content TypePGP
PGP//OpenPGP
OpenPGPRFC 7107 / Informational
Object Identifier Registry for
the S/MIME Mail Security
Working GroupRFC 7929 / Experimental
DNS-Based Authenticationof Named Entities (DANE)
Bindings for OpenPGP
RFC 8162 / Experimental
Using Secure DNS to
Associate Certificates with
Domain Names for S/MIME

RFC 7508 / Experimental
Securing Header Fields with
S/MIME

RFC 7114 / PS
Creation of a Registry forsmime-type Parameter
ValuesRFC 6210 / Experimental
Experiment: Hash Functions
with Parameters in the
Cryptographic Message
Syntax (CMS) and S/MIME

RFC 5753 / Informational
Use of Elliptic Curve
Cryptography (ECC)
Algorithms in Cryptographic
Message Syntax (CMS)

RFC 6211 / Informational
Cryptographic Message
Syntax (CMS) Algorithm
Identifier Protection Attribute

RFC 7281 / Informational
Authentication-Results
Registration for S/MIME
Signature Verification

RFC 8017 / Experimental
PKCS #1: RSA
Cryptography Specifications
Version 2.2

RFC 5754 / PS
Using SHA2 Algorithms with
Cryptographic Message
SyntaxRFC 4853 / PS
Cryptographic Message
Syntax (CMS) Multiple
Signer Clarification

RFC 5652 / STD 70
Cryptographic
Message Syntax(CMS)

RFC 5967 / Informational
The application/pkcs10
Media TypeRFC 5911 / Informational
New ASN.1 Modules for
Cryptographic Message
Syntax (CMS) and S/MIME

RFC 6268 / Informational
Additional New ASN.1 Modules
for the Cryptographic Message
Syntax (CMS) and the Public Key
Infrastructure Using X.509 (PKIX)
RFC 6318 / Informational
Suite B in
Secure/Multipurpose
Internet Mail Extensions(S/MIME)

RFC 5008 / Informational
Suite B in
Secure/Multipurpose
Internet Mail Extensions(S/MIME)

RFC 4134 / Informational
Examples of S/MIME
Messages

DomainKeys
DomainKeys//DKIM
DKIM

RFC 6109 / Informational
La Posta Elettronica
Certificata - Italian Certified
Electronic Mail

RFC 5752 / PS
Multiple Signatures in
Cryptographic Message
Syntax (CMS)

RFC 3853 / PS
S/MIME Advanced Encryption
Standard (AES) Requirement
for the Session Initiation
Protocol (SIP)

RFC 3211 / PS
Password-based Encryption
for CMS

RFC 6664 / Informational
S/MIME Capabilities for
Public Key Definitions

RFC 3855 / PS
Transporting
Secure/Multipurpose
Internet Mail Extensions(S/MIME) Objects in X.400

RFC 3183 / Experimental
Domain Security Services
using S/MIME

1998

RFC 5035 / PS
Enhanced Security Services(ESS) Update: Adding
CertID Algorithm Agility

RFC 4262 / PS
X.509 Certificate Extension
for Secure/Multipurpose
Internet Mail Extensions(S/MIME) Capabilities

Authentication-Results
Authentication-Results

SenderSenderID
ID//SPFSPF

RFC 6637 / PS
Elliptic Curve Cryptography(ECC) in OpenPGP

RFC 5751 / PS
Secure/Multipurpose
Internet Mail Extensions(S/MIME) Version 3.2
Message Specification

RFC 2630 / PS
Cryptographic Message
SyntaxRFC 7410 / PS
A Property Types Registry
for the AuthenticationResults Header Field

RFC 6376 / STD 76
DomainKeys Identified Mail
(DKIM) Signatures

RFC 5581 / PS
The Camellia Cipher in
OpenPGPRFC 3851 / PS
Secure/Multipurpose
Internet Mail Extensions(S/MIME) Version 3.1
Message Specification

RFC 3370 / Informational
Cryptographic Message
Syntax (CMS) Algorithms

RFC 6577 / Informational
Authentication-Results
Registration Update for
Sender Policy Framework(SPF) Results

RFC 6541 / Experimental
DomainKeys Identified Mail
(DKIM) Authorized ThirdParty Signatures

RFC 2633 / PS
S/MIME Version 3 Message
Specification

RFC 2986 / Informational
PKCS #10: Certification
Request Syntax
Specification Version 1.7

RFC 7601 / PS
Message Header Field for
Indicating Message
Authentication Status

RFC 6377 / BCP 167
DomainKeys Identified Mail
(DKIM) and Mailing Lists

RFC 2312 / Historic
S/MIME Version 2
Certificate Handling

Privacy,
Privacy,Email
EmailAuthentication,
Authentication,Anti-Abuse
Anti-Abuse
1997

RFC 4870 / Informational
Domain-Based Email
Authentication Using Public
Keys Advertised in the DNS(DomainKeys)

RFC 5750 / PS
Secure/Multipurpose
Internet Mail Extensions(S/MIME) Version 3.2
Certificate Handling

RFC 2785 / Informational
Methods for Avoiding the"Small-Subgroup" Attacks on
the Diffie-Hellman Key
Agreement Method for S/MIME

1996

RFC 5863 / Informational
DomainKeys Identified Mail
(DKIM) Development,
Deployment, andOperations

RFC 3850 / PS
Secure/Multipurpose
Internet Mail Extensions(S/MIME) Version 3.1
Certificate Handling

RFC 2631 / PS
Diffie-Hellman Key
Agreement Method

1995

RFC 5585 /Informational
DomainKeys Identified
Mail (DKIM) Service
Overview

RFC 2632 / PS
S/MIME Version 3
Certificate Handling

RFC 2315 / Informational
PKCS #7: Cryptographic
Message Syntax Version 1.5

1994

RFC 5016 / Informational
Requirements for a
DomainKeys Identified Mail
(DKIM) Signing Practices
ProtocolRFC 2311 / Historic
S/MIME Version 2 Message
Specification

RFC 3278 / PS
Use of Elliptic Curve
Cryptography (ECC)
Algorithms in Cryptographic
Message Syntax (CMS)

Authentication
AuthenticationStatus
StatusRFC 7208 / PS
Sender Policy Framework(SPF) for Authorizing Use of
Domains in Email, Version 1

RFC 4880 / PS
OpenPGP Message Format

RFC 2314 / Informational
PKCS #10: Certification
Request Syntax Version 1.5

1993

RFC 7001 / PS
Message Header Field for
Indicating Message
Authentication Status

RFC 4408 / Experimental
Sender Policy Framework(SPF) for Authorizing Use of
Domains in E-Mail, Version
1

RFC 3156 / PS
MIME Security with
OpenPGPRFC 2985 / Informational
PKCS #9: Selected Object
Classes and Attribute Types
Version 2.0

RFC 7372 / PS
Email Authentication
Status Codes

RFC 7960 / Informational
Interoperability Issues between Domainbased Message Authentication,
Reporting, and Conformance (DMARC)
and Indirect Email Flows

RFC 6686 / Informational
Resolution of the Sender
Policy Framework (SPF)
and Sender ID Experiments

RFC 2440 / Informational
OpenPGP Message Format

RFC 2437 / Informational
PKCS #1: RSA
Cryptography Specifications
Version 2.0

RFC 7489 / Informational
Domain-based Message
Authentication, Reporting,and Conformance (DMARC)

RFC 6449 / Informational
Complaint Feedback Loop
Operational
Recommendations

RFC 6212 / PS
Authentication-Results
Registration for Vouch
by Reference Results

RFC 4686 / Informational
Analysis of Threats
Motivating DomainKeys
Identified Mail (DKIM)

RFC 2726 / PS
PGP Authentication for
RIPE Database Updates

DMARC
DMARC

RFC 6692 / PS
Source Ports in Abuse
Reporting Format (ARF)
Reports

RFC 5451 / Informational
Message Header Field for
Indicating Message
Authentication Status

RFC 2480 / PS
Gateways and MIME
Security Multiparts

RFC 2015 / PS
MIME Security with Pretty
Good Privacy (PGP)1992

RFC 3939 / PS
Calling Line Identification for
Voice Mail Messages

Abuse
AbuseReports
Reports

RFC 4407 / Experimental
Purported Responsible
Address in E-Mail Messages

RFC 2635 / FYI 35
DON'T SPEW A Set ofGuidelines for Mass
Unsolicited Mailings andPostings (spam*)MIMEMIMESecurity
SecurityMultiparts,
Multiparts,MOSS
MOSS

RFC 6430 / PS
Email Feedback
Report Type
Value: not-spam

RFC 5518 / PS
Vouch By Reference

Vouch
Vouch

RFC 3938 / PS
Video-Message MessageContext

RFC 3459 / PS
Critical Content Multipurpose Internet Mail
Extensions (MIME)
Parameter

RFC 1847 / PS
Security Multiparts for
MIME: Multipart/Signed andMultipart/Encrypted

RFC 1848 / Historic
MIME Object Security
Services

RFC 4356 / PS
Mapping Between theMultimedia Messaging
Service (MMS) and Internet
Mail

RFC 2421 / PS
Voice Profile for Internet
Mail - version 2

RFC 3458 / PS
Message Context forInternet Mail

Message
MessageFormat,
Format,MIME
MIME

82 84 86 88 90 91

RFC 6591 / PS
Authentication Failure
Reporting Using the Abuse
Reporting Format

2003

2004

2005

S/MIME
S/MIME
2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017