Loving your work. I donated the other day and will likely do so again in future, as this stuff just keeps getting better! Anyway... onto my suggestion:
I'd love it if cmq could set a cron job to check the queue size every X minutes and drop me an email if the size exceeds X messages. This feature would have actually saved me from downtime a few days ago, when I failed to spot a spammer going to town on my server. I hope that's something you can consider adding to cmq. I know I'm not alone in wanting an easy way to keep tabs on my mail queue sizes
