If you are not using the Email2Fax gateway, but rather using the FAXmaker for Networks client, you must secure the mailbox directories, so that other users cannot browse them. This is achieved using Windows NTFS.
- Now go to the security tab. Remove 'Everyone' and add the user who owns the mailbox. Now also add the administrator account (assuming you are using the administrator account for the FAXmaker fax server and MTA). Click OK. The mailbox is now secured against unauthorised access.
IMPORTANT: If you don't add the administrator account then the FAXmaker server will not be able to access the mailbox and thus not send or receive faxes for this user.