The Review Booster history screen lists any past Email or SMS boosters you have sent along with their results.
Navigate to Invitations >> Review Booster
Click on Booster History
Click on Email Booster or SMS Booster tab to see the date sent, the type of booster (Company or Product) and the total number of invitations sent and reviews collected.
If you were curious with why you had received any errors, you can simply click on the error number and you will be given a drop down showing which line of the CSV the error was related to and why the error occurred e.g. Duplicate email.