Re: Recognize mbox files?

[Alfred M\. Szmidt]

       I still do not understand how this will work for find-file on a
       RMAIL file.  Before you could just do C-x C-f on a RMAIL file,
       and it would open in rmail-mode.  Could someone explain how
       this would work by using X-RMAIL-ATTRIBUTES?

   Emacs would check for X-RMAIL-ATTRIBUTES: in the first message,
   find it, and visit the file using Rmail.

So such a check would be needed for _every_ file one does a find-file
on.  What would happen if you have a legal non-mbox file, that
contains X-RMAIL-ATTRIBUTES?