If you have an Exchange email account on your iPhone, you can delete it by going to the Accounts section of the iPhone’s Settings and clicking on the Delete Account button.
Delete the profile if your iPhone has one. If you have an iPhone with a corporate email account, there’s probably a profile already on it. To delete this profile, go to Settings > General > Profile and then Remove Profile.
After the deletion of your Exchange account, you will be restored to the list of your accounts. Tap Add Account from this menu.
If your exchange contacts are kept on iCloud.com, go to Settings>Mail, Contacts, Calendars… and change the setting for your exchange account to “selected”. Delete or turn off contact syncing if you want your phone’s and iCloud’s exchange contacts gone.
