Usage says mail app 2.4GB

I'm using an ipad2 with Os 7.1.1 I think.

OF course 32GB is not enough and am trying to free up space.

Under the settings tab - usage it lists all of your apps and how much room they require. The biggest one is mail, 2.4GB

I have deleted every email on all three accounts I have (bulk deleting email was a doozy btw) and the program still takes up 2.4GB

HOw do I gain back memory. There is no way mail is that memory intensive.

thanks in advance for your assistance