I always thought the five control-A's were a failure of imagination (never going to send binary?).
As always, it's about history and how they got there. What was reasonable for one group, over time was not for another.
True. I joined BBN after the TCP/IP flag day, after 4.2BSD, and so on. When I used MH, it kept one message/file; I only know the control-a thing from MMDF.
Rich, that was a much later version.
FWIW: The big complaint about MH was not the mailbox format, it was that Bruce stored your files in separate files, which on a small machine like a PDP-11, eats up inode space, although it made doing things like grep and finding something easy.
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