I have a dozen of email accounts and a couple of them are available directly from my Outlook 2013.

One thing I really hated since the 2013 version is that it wasn't possible to rename some of the accounts (those connected to Exchange for example).

I have done some other research today and I found an easy way. There is an application that seems to connect to the registry and change the display name property.

Interested? Check http://www.howto-outlook.com/howto/renameaccountandmailbox.htm#exchange