mbox spliting tool ?

Does anyone know of a tool/script for spliting large Unix mbox files up into smaller chunks ?

What I want is something that will take a large mbox file and split it into smaller ones based on some criteria (in most cases I probably want it split up by the year received, but in some cases I probably want it split down to the month level).

I'm sure there must be something like this out there already, though I haven't managed to find anything by Googling.

Will grepmail do it?

Peter

It might do, just jumping through a few CPAN hoops so that I can get it running...

It took nearly two hours of CPAN wrangling to get grepmail to finally build, but I managed it in the end.

It looks like it is just what I need (or nearly at least). I'll need to wrap it up in a few of my own scripts to get it to do just what I need.

Thanks Peter