I will add references to this list as I come across them.
Another list of email-history sources is at:
My eventual goal will be to merge this list into that so that is the definitive list, and this list then will only include any citations not included in that list.
No doubt other email systems were developed that are not mentioned in the various relatively objective histories of email. However, whatever unique feature such an email system might have had (if considered unique when reviewed by professional historians without an invented-here bias) surely doesn't qualify one of these systems as the instance of the invention of email, especially if it was unknown in the mainstream community developing email over several decades.
In February 2012 there was a Washington Post story about the transfer to the Smithsonian of documents, listings, etc., of an implementation of a system developed beginning circa 1978 by Shiva Ayyadurai that he called "EMAIL." The story called him the "inventor of email." Even accepting that such a system actually operated doing email (I suspect that few, if any, of the people involved in the mainstream of email development and use of those systems over the decades had heard previously of Ayyadurai's system), having built that system and named it EMAIL hardy makes Ayyadurai an important contributor to the development of email, and surely does not make him inventor of email. It only makes him the developer ("inventor," if you will) of his system named EMAIL and one of many people who developed email systems unsung in the mainstream history of email. In my mind, Ayyadurai's hard sell campaign to have what he did be defined as the instant of the invention of email, with him defining everything prior as proto-email and everything later as after-the-invention-of-email, is at least unseemly—touting his effort as having primacy over the efforts of so many other people.
I see some problems with debating who-was-first issues via "the media": (1a) there is risk that the media will see the controversy itself as news and help perpetuate the controversy rather than seeking to resolve it by seeking the objectively accurate (often complex) history; (1b) alternatively, the media can have a mechanical sense of fairness which gives equal time to obviously incorrect views just because they are vigorously expressed; (2) the more a topic (e.g., "inventor of email") is heard about by the lay public (even to refute an assertion), the more likely the lay public is to assume something stated about the topic is true (familiarity can result in unthinking unfounded of assertions).
Another problem in the Ayyadura situation is that various members of the media have taken Ayyadura's having copyrighted a program named EMAIL as evidence that he has a legitimate claim to have invented email and, for some, even that he owns the word "EMAIL." But his copyright actually proves very little.
[This page] Copyright 2012 by David C. Walden
The preceding sentence says nothing about whether the concepts and opinions I am espousing on this page are first or unique. I copyrighted it indicating I am claiming "ownership" of this set of paragraphs of words I just made up.
Copyrights are not granted; they are asserted. In fact, we hold a copyright for our creations (such as this page) whether we state them or not. In this sense the pre-Ayyadura email programs were also copyrighted, and (for all I know) some of them may have had copyright notations on them.
Registering a copyright merely publicly records the assertion of a copyright.