Syncing Outlook 2002 over Internet

A few people in my office has asked me how they can sync Outlook 2002 (including Calendar, Notes, Tasks, Inbox etc) between workstations over the Internet. The office workstations are members of a domain, but remote access is not set up. And setting up a VPN would be too big a task.

I have thought about setting up a FTP server, and have FTP clients to automatically synchorize files at pre-determined times. But it is a big security hazard and I am reluctant to do so.

Are there simple ways to get this working? Your suggestions are greatly appreciated!