Information Rights Management in Office 365 Documents
Microsoft has two methods to enable IRM within the Office 365 productivity suite (Word, Excel and PowerPoint). The first is to install the IRM services on a Windows 2003 or 2008 server, which enables integration within a corporate Windows domain. This integration allows a content author to select which users and groups from Active Directory have access to their content. The second method is to use a Windows Live ID. This enables companies without an Active Directory environment to restrict user access based on a user's email address.