gnus: nnmairix requirements

 
 8.2.2 nnmairix requirements
 ---------------------------
 
 Mairix searches local mail—that means, mairix absolutely must have
 direct access to your mail folders.  If your mail resides on another
 server (e.g., an IMAP server) and you happen to have shell access,
 ‘nnmairix’ supports running mairix remotely, e.g., via ssh.
 
    Additionally, ‘nnmairix’ only supports the following Gnus back ends:
 ‘nnml’, ‘nnmaildir’, and ‘nnimap’.  You must use one of these back ends
 for using ‘nnmairix’.  Other back ends, like ‘nnmbox’, ‘nnfolder’ or
 ‘nnmh’, won’t work.
 
    If you absolutely must use mbox and still want to use ‘nnmairix’, you
 can set up a local IMAP server, which you then access via ‘nnimap’.
 This is a rather massive setup for accessing some mbox files, so just
 change to MH or Maildir already...  However, if you’re really, really
 passionate about using mbox, you might want to look into the package
 ‘mairix.el’, which comes with Emacs 23.