Go to Admin -> Account Management -> Reports -> Usage Reports -> Active Hosts. Select the date ranges you want, then the display major sort (By Meetings or By Users).
THEN when you see the meetings or hosts that you want, click the Generate details report link. You'll be taken to the Report Queue tab where it will seem like forever for your report to generate... but refreshing the page after 5-10 seconds will usually get your report to show up as downloadable.
The resulting display will have lots of details... but note that the Email address field is ONLY populated with users in your account, or user registered for an event.