I've been looking for a bit but can't find a free/open-source tomcat 7 monitoring tool that will send out e-mails or notifications when certain situations occur. For example when CPU utilization spikes or RAM is consistently full. Things Like that.
I've looked at JMelody and Psi-Probe and neither of them have the ability to send e-mails when some event occurs.
You can take a look at jboss RHQ