I get lots of email from cron jobs. I probably spend 5-10 minutes every day clicking through them and making sure that there's nothing "odd" in them which needs my attention.
I would love to have some software which reads my cronmail, figures out what's "normal", and warns me when something isn't normal.
I don't know the scope of Colin's cron problems, but filtering out mail in this case seems like a less preferable solution than simplifying the way cron does email to begin with. Filtering e-mail in this case is like putting your fingers in your ears when you walk by a loud stereo you've left on instead of just turning it off. As a developer, cron doesn't give me a lot of control over where e-mail is sent unless I jump through hoops to give myself that control. Ignoring the complexity of the reports, and the fact that filters like that don't easily scale across different recipients, the fact is that cron's e-mail capability is extremely coarse-grained. For every run of every job, the entire output is e-mailed out to the address specified in the crontab. This gets very unwieldy.
I've had to write cron table entries with a blank mail recipient in the crontab itself, and handle the specific mailing cases in the job script. This sucks. I'm not sure I think the solution is something that reads cron-mail and automatically generates filters, but I would very much like it if cron supported e-mail lists based on return codes or something else like that.
I would love to have some software which reads my cronmail, figures out what's "normal", and warns me when something isn't normal.