[Exim] Need Recommendation: Backend Store for Virtual Accoun…

--
[ Picked text/plain from multipart/alternative ]
I need a recommendation for a backend to store virtual accounts in exim.

In my office, I\'ve got exim and courier imap tied into our ldap
server, using company wide passwords and accounts from ldap to handle
mail.

It works great -- but its a bit overkill for my personal web machine. 
I'd like that to run exim, and handle virtual accounts with something
simpler than ldap -- perhaps dbm or a flatfile.

Can anyone point me to a setup they've enjoyed in the past.

--