OT - archiving mail

[Richard Lyons <richard@the-place.net>]

I know this is not really the forum, but all the bright people who can 
contribute to this are here...

For years, I've kept a substantial hierarchy of "folders" in my mail 
client, reflecting a filing system similar to that for other files in 
my home directory.  Currently there are over a hundred folders nested 
up to three levels.  Many are automatically filtered, but it's pretty 
easy to drag and drop files to where they belong (using Kmail or any 
GUI client) so this clumsy system has stayed and grown.  But there are 
disadvantages:
  - If I read the ~/Mail directory from mutt, I only get to see the 
    top level folders.  If I convert it to a flat structure, there will
    be over 100 folders to scroll through to find or file anything.
  - I have to use mbox because when I travel (and copy all the current 
    folders to, say, a smart media card) I cannot copy maildir files 
    -- apparently the various non-alphanumeric characters in the 
    filenames trip up 'cp -r'
  - The whole thing is big and clumsy.
  - It duplicates another filing system, so locating documents for a job
    entails looking in two places.

It struck me I can copy job and topic emails to the non-mail file 
system, and get rid of them from the email folders as soon as they are 
answered.  But that has to be done one at a time - no drag-and-drop 
possible either.  List emails are easy - they get filtered to their own 
folder and purged after suitable time.  It's things that I need to keep 
long-term that gum up the system.  Does anyone here have a neater way 
of handling this kind of thing, or can suggest some shortcuts or at 
least a batch script to transfer the emails to external files?

TIA
-- 
richard