1)      Log onto webmail

2)     In the left hand pane right-click on your name and choose Add shared folder…

                                

3)      Type the Email Account Name into the field and click Add

4)      You should now see Mailbox – AccountName below your regular mailbox folders

5)      This shared account is now a part of your webmail login  and you will see it on every computer that you use to access your email

6)      If for any reason it needs to be removed you can right-click on the shared Mailbox – AccountName and choose Remove shared folder