Michael Lumb was up against a demand for a very rigid structure in his thesis. Somewhere I've read about the problems he had with the academic committees in his school that shaped the outcome of his thesis. Also his emphasis was on the history of mail art with a bit in the end about the future of mail art based on the survey he circulated at the time.
I am lucky that my committee does not micromanage my research like Michael's committee did. My committee members actually want me to write a lively arty/lively/techie/experimental book filled with mail art and reports of mail artists on the Internet. I am going at it in a way that I think most reflects the mail art style respecting original documents and using the unfiltered voices of mail artists to talk about their own work.
Of course, I will have to draw conclusions at the end like Michael did, but I plan to post the whole thing on the web with an open-ended structure, such as a guest book or journal, so that mail artists or anyone else can continue to add to the text and to the references.
My next goal is go to artpool and explore their website in as great a detail as TAM. I don't know of any other mail art website that has as comprehensive a mission in regard to mail art.
As for Saper's book, it covered a much broader spectrum than Lumb's thesis. Saper had an outsiders' perspective, so there is a strong contrast between Saper's book and Lumb's thesis written by a practitioner. Saper wrote to me that he was also limited by an academic committee and publisher. It seemed to me that he had some problems developing meanings from the archives he researched without direct knowledge of the social context and the people involved in making the archived documents. Reading his book highlighted the strengths gained when mail artists, no matter how academically unqualified, research and write about their own understandings, creations, and connections. Saper's strength was that he provided great links to theory that are important to understanding ways that the Mail Art network overflows beyond its isolated internal meanings.
I've been thinking a lot about issues involve in writing about mail art, working in two (or more) networks, encouraging mail artists to speak with their own words and images for publication, and creating a book that somehow captures the present issues of mail art and Internet confluence.