Mail Backup

[tenone <tenone () gmail com>]

Hi,

 May I know if there is a way/program/script that can backup emails on 
a sendmail linux server when users are downloading their mail thru POP3? 

 Basically, I want to keep a backup copy of /var/spool/mail/username ( 
which contain a copy of all their mail for a week/month) on the server 
for around one week in case the users accidentally delete their emails 
after they have downloaded them to the local computer.

Thanks for any suggestions!