rmail-bury in RMAIL
runs the function "rmail-bury".
What this does it bury (that is, remove from the screen) the current
Rmail buffer and its summary buffer.
This is a "privacy" function, clearing your screen of any mail you may
The easiest way to get back to reading mail after this is
If, after understanding it's real function, you'd still like to break
it, I'd suggest redefining it as the command you probably thought you
wanted (to back up one message).
(define-key rmail-mode-map "b" 'rmail-previous-undeleted-message)))