Don't delete old mail automatically or unintentionally in gnus

[Don Saklad]

Questions
1. about how to make sure that old mail is not deleted
   automatically
   or unintentionally;

   a definitive statement on what to do to prevent automatic `expiration'
   of old files.

   According to both Stein A. Stromme  stromme (a little snail at sign) 
mi.uib.no
   and David Maze  dmaze (a little snail at sign) mit.edu  the latest version
   of gnus will not delete old mail.

   For removal, it's necessary mark mail messages explicitly.

   This is a reversal of the previous default according to the then manual,
   in which mail messages were deleted automatically. Email message were
   treated as previously-read news articles; it had been necessarly to
   take special measures to avoid having gnus delete them after a period.

   Unfortunately, it's neither apparent which versions of gnus are safe;
   nor how to ensure that messages are safe indefinately.



2. about how to highlight each of the following differently from each other
   and from that which is `old and read'
   and from that which is marked for deletion,
   a minimum of 7 different highlighting looks:

   in the *Group* buffer

   Summary buffer with any unread new email in it
   Summary buffer with any unread old email in it
   Summary buffer with only email in it that has all been read

   in a *Summary* buffer

   new unread email messages
   old unread email messages
   old previously read email messages

   in any buffer

   that which is marked for deletion or expiration

   Some people use different colors for highlighting, some people use
   different fonts or different `voices' in their Emacspeak.



3. about how to use spamassassin in conjunction with a second spam filter, such 
as
   `ifilter', and the gnus fancy splitting features to put suspected spam
   into a different file when mail comes from an mbox on the local machine.