By default, IFS creates an instance of your mailbox and public folder stores on the M: drive (a virtual drive) and shares the drive with a share name of BackOfficeStorage. This drive on your servers would be seen as \\<servername>\BackOfficeStorage and \\<servername>\BackOfficeStorage, etc.
The IFS (Installable File System) makes mailboxes and public stores available as standard folders and files, thus they are available to all Windows applications such as Word, Internet Explorer and the command prompt.
- Claulle