From Jim Larus History
In 1987 I went to work for Bolt Beranek and Newman, as Jim had before me. In my previous job, I had been using RMAIL, but as my folders tend to run large, I was frustrated with the speed of RMAIL. However, I stuck with it because I wanted the GNU Emacs interface. I am very familiar and comfortable with the Emacs interface (with just a few modifications of my own) and dislike having to use applications with embedded editors; they never live up to Emacs.
MH is the mail reader of choice at BBN, so I converted to it. Since I didn't want to give up using an Emacs interface, I started using mh-e. As is my wont, I started hacking on it almost immediately. I first used version 3.4m. One of the first features I added was to treat the folder buffer as a file-visiting buffer: you could lock it, save it, and be warned of unsaved changes when killing it. I also worked to bring its functionality a little closer to RMAIL. Jim Larus was very cooperative about merging in my changes, and my efforts first appeared in version 3.6, distributed with Emacs 18.52 in 1988. Next I decided mh-e was too slow and optimized it a lot. Version, 3.7, distributed with Emacs 18.56 in 1990, was noticeably faster.
When I moved to the X Consortium I became the first person there to not use xmh. (There is now one other engineer there using mh-e.) About this point I took over maintenance of mh-e from Jim and was finally able to add some features Jim hadn't accepted, such as the backward searching undo. My first release was 3.8 (Emacs 18.58) in 1992.
Now, in 1994, we see a flurry of releases, with both 4.0 and 5.0. Version 4.0 added many new features, including background folder collection and support for composing MIME messages. (Reading MIME messages remains to be done, alas.) While writing this book, Bill Wohler gave mh-e its closest examination ever, uncovering bugs and inconsistencies that required a new major version to fix, and so version 5 was released.
Stephen Gildea, June 1994From Jim Larus History