[Exim] procmail

Hi,

Right now I have my mailusers added simply by adduser. They have no valid shell, but they are added.
I want exim do everything from mysql (maybe I will install qpopper or do you recommend some other?).

In this case how I could let my users (if they are not added unix way) to run .procmailrc, because some of them run procmailrc to send the topic of the new mails to an another address at their mobil (SMS) provider?

Thanks!
Mihaly Litzler