I setup the option for a Calendar for all employees within the 365 portal. I had to setup the Public Folders to complete this process. I have one user that when he opens his Office 365 Outlook client a window pops up which I have included as an attachment. This popup is actually asking for credentials for the Public Folders email account. This is odd because I have never assigned this account to anyone in relation to permissions other than myself for testing. It makes no sense how his account would even know the new Public Folder account even exists in the system at this point.