using GNUS as mail reader for mbox archives

using GNUS as mail reader for mbox archives

[David NovogrodskyWrk]

I am running emacs 21.1 on Mac OSX. I would like to import my mbox
mail files from Apple's mail program into GNUS. My GNUS mail backend
is set to nnml. Here is the procedure I follow:
   ***Go to the group buffer. 
   ***Type `G f' and give the path to the mbox file when prompted to
   create an nndoc group from the mbox file.. 
    (I enter the path to thye mbox file, usually
         ~/Mail/archive/Cocoon-DocumentationList.mbox
   ***Type `SPACE' to enter the newly created group. 

When I press space, I get the error, can't find the file or
buffer. No such buffer exists. Here are some of my other settings:

        (setq gnus-secondary-select-methods '((nnml "Private" 
               ;; spool directory for the nnml mail backend
               (nnml-directory "~/mail/")
               ;; mail active file
               (nnml-active-file "~/mail/active"))))

Any idea what is wrong?

Thank you,
David N.