This is fairly easy if you actually know where to look. And believe me, the first time I attempted to do this, I got lost.
Getting straight to the point, here is how to remove an account in the Android Email App:
1. Main Apps Menu > Settings > ACCOUNTS > Corporate
2. Select the desired account (should have a green ‘sync’ icon to the left of the account name)
3. Next screen should say ‘Sync’ in the upper left of the header navigation bar. Choose the far right ‘3 dots’ drop down menu
4. Choose “Remove account”