I think I know what you're asking... I do this from an nDepth search within LEM.
On the Monitor tab, you should see a filter for "Rule Activity" in the Overview section. Highlight it and then click the gear icon on top and choose send to nDepth. (otherwise just start a new nDepth search for "InternalRuleFired"). Now you can change the time frame. I use Last Week because it's a scheduled report. Once you get the results, look at the extraneous info field. You can filter based on the extraneous info if you only want to see emails, host incidents, etc. When it's an email, it lists the email address it was sent to. You can export the results to .CSV to further play with the data if you want. Hopefully that helps.