Some people have reported issues using Exchange Server 2007 and 2010 on iOS 6. A temporary fix has been discovered and here are the steps to follow to start receiving your Exchange email again:
Step 1) Go to Settings > Mail, Contacts, Calendar > Fetch New Data and make sure it is set to Push.
Step 2) Go to Settings > Mail, Contacts, Calendar > click on your Exchange account > click on Days to Sync > change it to a different setting (something different from what you have now, you can change it back later).
Step 3) Go to Settings > Mail, Contacts, Calendar > click Show > change to a different value (again, something other than what you have now).
Step 4) Reboot your iOS 6 device.
Step 5) Test out Exchange by sending yourself an email. Push should be working and you should be able to send and receive emails from your account now!
Let me know if this helped you and also let me know if it did not help you! Comments and questions are always welcome so feel free to leave them below!