- RFC821
J.B. Postel: Simple Mail Transfer Protocol, August 1982
- RFC822
D.H. Crocker: Standard for the Format of ARPA Internet Text Messages, August 1982
- RFC1123
R. Braden: Requirements for Internet Hosts -- Application and Support, October 1989
- RFC1321
R. Rivest: The MD5 Message-Digest Algorithm, April 1992
- RFC1734
J. Myers: POP3 AUTHentication command, December 1994
- RFC1738
T. Berners-Lee, L. Masinter, M. McCahill: Uniform Resource Locators (URL), December 1994
- RFC1869
J. Klensin, N. Freed, M. Rose, E. Stefferud, D. Crocker: SMTP Service Extensions, November 1995
- RFC1891
K. Moore: SMTP Service Extension for Delivery Status Notifications, January 1996
- RFC1939
J. Myers, M. Rose: Post Office Protocol - Version 3, May 1996
- RFC1951
P. Deutsch: DEFLATE Compressed Data Format Specification - Version 1.3, May 1996
- RFC1952
P. Deutsch: GZIP file format specification - Version 4.3, May 1996
- RFC1957
R. Nelson: Some Observations on Implementations of Post Office Protocol (POP3), June 1996
- RFC2015
M. Elkins: MIME Security with Pretty Good Privacy (PGP), October 1996
- RFC2045
N. Freed, N. Borenstein: Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies, November 1996
- RFC2046
N. Freed, N. Borenstein: Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types, November 1996
- RFC2047
K. Moore: Multipurpose Internet Mail Extensions (MIME) Part Three: Message Header Extensions for Non-ASCII Text, November 1996
- RFC2048
N. Freed, J. Klensin, J.B. Postel: Multipurpose Internet Mail Extensions (MIME) Part Four: MIME Registration Procedures, November 1996
- RFC2049
N. Freed, N. Borenstein: Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples, November 1996
- RFC2104
H. Krawczyk, M. Bellare, R. Canetti: HMAC: Keyed-Hashing for Message Authentication, February 1997
- RFC2152
M. Davis, D. Goldsmith: UTF-7, a Mail-Save Transformation Format of Unicode, May 1997
- RFC2183
S. Dorner, K. Moore, R. Troost: Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field, August 1997
- RFC2195
J. Klensin, R. Catoe, P. Krumviede: IMAP/POP AUTHorize Extension for Simple Challenge/Response, September 1997
- RFC2222
J. Myers: Simple Authentication and Security Layer (SASL), October 1997
- RFC2231
N. Freed, K. Moore: MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations, November 1997
- RFC2277
H. Alvestrand: IETF Policy on Character Sets and Languages, January 1998
- RFC2279
F. Yergeau: UTF-8, transformations format of Unicode and ISO 10646, January 1998
- RFC2368
P. Hoffman, L. Masinter, J. Zawinski: The mailto URL scheme, July 1998
- RFC2425
F. Dawson, T. Howes, M. Smith: A MIME Content-Type for Directory Information, September 1998
- RFC2426
F. Dawson, T. Howes: vCard MIME Directory Profile, September 1998
- RFC2449
R. Gellens, C. Newman, L. Lundblade: POP3 Extension Mechanism, November 1998
- RFC2476
R. Gellens, J. Klensin: Message Submission, December 1998
- RFC2554
J. Myers: SMTP Service Extension for Authentication, March 1999
- RFC2595
C. Newman: Using TLS with IMAP, POP3 and ACAP, June 1999
- RFC2646
R. Gellens: The Text/Plain Format Parameter, August 1999
- RFC2821
J. Klensin: Simple Mail Transfer Protocol, April 2001
- RFC2831
P. Leach, C. Newman: Using Digest Authentication as a SASL Mechanism, May 2001
- RFC3030
G. Vaudreuil: SMTP Service Extensions for Transmission of Large and Binary MIME Messages, December 2001
- RFC3207
P. Hoffman: SMTP Service Extension for Secure SMTP over Transport Layer Security, February 2002
- RFC3447
J. Jonsson, B. Kaliski: Public-Key Cryptography Standards (PKCS) #1: RSA Cryptography, Specifications Version 2.1, February 2003