Alessio Cecchi wrote:

We run a script that is kicked off via cron every 10 minutes, doing a sanity check on various system functions. If you allow your users to change system files, sooner or later they'll mess them up or delete them. A script run periodically can either notify you of a potential problem, or fix it depending on the script logic.

For example, every 10 minutes we run through each virtual domain and calculate what the legitimate email addresses are for that domain and tell qmail to only accept mail for addresses that are deliverable for that domain. We use a feature of the spamcontrol patch that uses a separate file during the smtp session to say who is a legitimate recipient. That file is recalculated every 10 minutes. If I had to remember to add or delete users manually from that file I know I'd mess it up sooner or later. Now, I can create a new user and within 10 minutes the script will add that user to the list of legit users. I don't have to think about it. Similarly, script something to hand out default filter files to anyone that doesn't have one.