Mail Folders
............

   `nnfolder' is a backend for storing each mail group in a separate
file.  Each file is in the standard Un*x mbox format.  `nnfolder' will
add extra headers to keep track of article numbers and arrival dates.

   Virtual server settings:

`nnfolder-directory'
     All the `nnfolder' mail boxes will be stored under this directory.

`nnfolder-active-file'
     The name of the active file.

`nnfolder-newsgroups-file'
     The name of the group descriptions file.  *Note Newsgroups File
     Format::.

`nnfolder-get-new-mail'
     If non-`nil', `nnfolder' will read incoming mail.

   If you have lots of `nnfolder'-like files you'd like to read with
`nnfolder', you can use the `M-x nnfolder-generate-active-file' command
to make `nnfolder' aware of all likely files in `nnfolder-directory'.