I am running an Xposed module that allows me to turn it off. I am also using Wanam Xposed that has the option in it as well.
If that doesn't work for you, you could always try MailWise Beta. They have an option to turn that off as well with a code. Download the app, before setting up your account, open the app, hit the menu button, click on exchange bypass and follow the instructions.
I'm loving K-@ Mail Pro - email evolved