Change Name that shows on Microsoft email

We have a general mailbox, it is currently showing the name of a past employee and we would like to change it to reflect a current employee.  I have changed it on the Comcast side, but it is not showing up under Microsoft Outlook.  Is there a way to fix this without having to delete the email from Outlook and then re-installing it?  We have the email on several machines and it would be a pain to do that to each one.