When installing the Phish Hook button for use in Microsoft Outlook please be aware that due to restrictions imposed by Microsoft, the Phish Hook button can only currently be used on "User" mailboxes and will not work for "Shared" Mailboxes.
Microsoft do plan to allow the use for "Shared" mailboxes in the future, however no current timeline is in place for this feature. Once this functionality becomes available, we will add it.