Is possible make a "email backup" of a determinated user

Is possible make a "email backup" of a determinated user (incoming and outgoing mail) .

I have a setup based on http://www.howtoforge.com/virtual_users_and_domains_with_postfix_debian_etch

PD: It is an order of the "boss"

Thanks for your help.

 

You can back up the /home/vmail directory.