I would like to suggest an enhancement. Currently one of this plug-in's criteria is:
"User has posted at least X messages in Y days:"
I don't want to display this notice to people who have posted X posts in Y days. I want to display notices to people who haven't posted in X days.
So the additional enhancement would be:
"User has not posted at least X messages in Y days."
On my forums I would use 1 messages in 30 days, to give notices to anyone who has not posted in a month, encouraging them to participate.