[Dovecot] Method of archiving mail?

[Stephen Allen]

Hello

I have a situation in which a number of users have 10,000+ messages in 
the maildir, going back a few years.  I'm not a fan of this many files 
lying around so I'd like to set up some kind of archiving, but one that 
will allow user's access to the old mails should they wish to see them.

I thought of a cron job trying to sift through messages pulling those 
what were older than x days, then writing some script to process a 
request from a user (date/time/from/to/subject/body text) and copy 
matching messages to a "query" folder in the maildir.  However, a) I'm 
not good at this kind of thing, and b) I have a feeling it's already 
been done before.

Can anyone point me in the right direction please... is their software 
around to do this already?

Many thanks,
Steve :)