archivemail - archive and compress old mail in your mailbox

'archivemail' is a tool written in Python for organising and storing old
email choking any of your mailboxes. It can move messages older than a
certain number of days to a separate 'archive' mailbox which can be
compressed with bzip2, gzip or compress. 

For example, have you been subscribing to the 'linux-kernel' mailing list
for the last 6 years and ended up with an 160-meg mailbox that 'mutt' is
taking a long time to load?  'archivemail' can move all messages that are
older than 6 months to a separate compressed mailbox, and leave you with
just the most recent messages. 

'archivemail' can save a lot of disk space and will significantly reduce
overhead on your mail reader. The number of days before mail is considered
'old' is up to you, but the default is 180 days.

'archivemail' currently works on mbox-format mailboxes, and requires python
v2.0 or greater. It also supports deleting old mail instead of archiving
it. It currently only works on Unix platforms.