Outlook Links

We have a number of Outlook 98 installations with various differant updates installed. Most are running on Windows NT.
When writting a email and typing \\Man.. to open a link to a file, it doesnt reconisge this a link.
This is also the case when the users are receiveing in comming mails with simular links on.
This works if you type the file: then the file location.

Can anyone help here??