To change the name for your Exchange mailbox, you can access it in the options in Outlook Web Access.
To change the name:
Article ID: 249
Created On: Fri, Mar 13, 2015 at 11:44 AM
Last Updated On: Thu, Apr 23, 2015 at 11:42 AM
Online URL: https://www.heartinternet.uk/support/article/how-do-i-change-the-display-name-for-my-exchange-mailbox.html