I have a Motorola Atrix phone running Android 2.3.6. I had just performed an update to my firmware and can no longer access my corporate email account via the "Email" app. I tried to re-add the account but would receive errors stating that the email had already been added (or email already exists). Everything on the Internet leads me to believe that I would have to perform a factory reset of the phone. Where did the email account go and how can I add the email if the phone says that it already exists or it was already added?
I am answering my own question.
The original email configuration still exists on the phone, but it cannot be accessed via the "Email" app. Accessing the "Email" app will just prompt you to add the account again (along with other account types like facebook, twitter; then it denies you stating that it already exists). Instead click on the "Messaging" app and then you will see the "disappearing" email account in addition to "Universal Account" and "Text Messaging". Select the original account and edit the account properties. On the account properties page you can "Remove Account". By removing the account you can then go and add it again successfully.
I have heard that others are doing a hard reset which is not necessary.