gnus: Not Reading Mail

 
 6.4.12 Not Reading Mail
 -----------------------
 
 If you start using any of the mail back ends, they have the annoying
 habit of assuming that you want to read mail with them.  This might not
 be unreasonable, but it might not be what you want.
 
    If you set ‘mail-sources’ and ‘nnmail-spool-file’ to ‘nil’, none of
 the back ends will ever attempt to read incoming mail, which should
 help.
 
    This might be too much, if, for instance, you are reading mail quite
 happily with ‘nnml’ and just want to peek at some old (pre-Emacs 23)
 Rmail file you have stashed away with ‘nnbabyl’.  All back ends have
 variables called back-end-‘get-new-mail’.  If you want to disable the
 ‘nnbabyl’ mail reading, you edit the virtual server for the group to
 have a setting where ‘nnbabyl-get-new-mail’ to ‘nil’.
 
    All the mail back ends will call ‘nn’*‘-prepare-save-mail-hook’
 narrowed to the article to be saved before saving it when reading
 incoming mail.