I am using Mhonarc to archive a mail list. The current archive is now 5000
First, I was wondering if there is a practical limit to the size
of an archive mhonarc can handle (for performance reasons mainly).
It all depends on how long your users are willing to wait when they
load the main index page. :)
In my experience, indices with more than 1500 messages start generating
complaints from our user base.
Second I am now looking for "automatic" solutions to break this archive in
parts (on a per semester or per year basis).
If you're doing it based on time, your best be is either to have an
automatic job move the archives to a new directory, or if you're under
Unix, preprocess the messages with procmail or a similar mechanism.