An MBOX viewer? (read that as view MBOX files without importing them into an email client?)

[MEG]

A friend uses and recommends mail steward pro for email archiving. Takes the mbox file and imports it into a mysql db keeping the attachments and all the meta data. Looking at the site it apparently comes in a Lite, regular and Pro version.

http://www.mailsteward.com

EDIT - Looks like there's a free version that will let you archive up to 15,000 emails to test it.