In the Email Campaign module, go to the "Sent" tab and click on the arrow next to the default dates.
In the custom range, change the dates there. The data can be displayed in a range of up to one year.
You can choose dates from :
- January 1st, 2015 to December 31st, 2015
- August 1st, 2019 to July 30th, 2020
but not :
- January 1st, 2016 to Match 31st, 2017 (the range is more than 1 year)