Archmbox is a simple email archiver written in perl: 
- parses one or more mailboxes
- selects some or all messages 
- performs specific actions on the selected messages.
At this time archmbox supports mbox and mbx mailbox formats.
 
Three different modes are available: 
- list mode, which is useful to list all selected messages  
- kill mode, if messages should be deleted from the mailbox(es) 
- archive mode, to archive the selected messages in a different mailbox 

Messages selection is based upon:
- date criteria
- absolute date 
- days offset 

It is also possible to refine the selection using regex on the header fields.
The archive mailbox can be saved in gz or bz2 compressed format as well.

WWW: http://adc-archmbox.sourceforge.net/