Typically, it works this way:
\\servername\drivename\foldername
You can even be specific and add the filename as well, if you incclude the
extension:
\\servername\drivename\foldername\filename.ext
Links may or may not be blocked by the server or even Outlook depending upon
the version and any Group Policies in place on the network.
Note that there can be NO spaces in any name in the link and the filepath
must match the names exactly. If the folder you're trying to link to has a
space in the name, this will not work.
Does this make sense for you?