Thanks for getting in touch!
Using our Busiest Hours metric, you can see the number of sent emails for each day of the week:
This is an aggregate of all the days of the week from the whole report period (Monthly or Weekly), however it is possible to generate a report for individual days using our Custom Reports!
You can access Custom Reports and all our other Premium features here.
Please let me know if you have any further questions or issues and I will be happy to help.