Email processes and protocols/Bibliography
[Crocker09] D. Crocker (2009) "Internet Mail Architecture", RFC-5598, http://ietf.org/rfc/rfc5598.txt.
[Gellens06] R. Gellens, J. Klensin (2006) "Message Submission for Mail", RFC-4409, http://ietf.org/rfc/rfc4409.
[Klensin08] J. Klensin, ed. (2008) "Simple Mail Transfer Protocol", RFC-5321, http://ietf.org/rfc/rfc5321.txt.
[PnD07] L. Peterson, B. Davie (2007) "Computer Networks: A Systems Approach" 4th ed. Sect. 9.1.1 "Electronic Mail", ISBN 0-12-370548-7.
[Resnick08] P. Resnick, ed. (2008) "Internet Message Format", RFC-5322, http://ietf.org/rfc/rfc5322.txt.
[Stevens94] W.R. Stevens (1994) "TCP/IP Illustrated, vol. 1, The Protocols", Chapter 28, "SMTP", ISBN 0-201-63346-9.
[Wikipedia08] Simple Mail Transfer Protocol. More details on SMTP, including history, abuse, and related protocols.