If other users can't follow your links:
• your administrator may not have given them access to the container
• they may not have permission to open objects in the container
• FirstClass may not be able to find the target object (for example, when a message containing a link is mailed to someone who isn't on your server).
If FirstClass can't find the target, and the target hasn't been deleted or moved since the link was made, the link may be relative instead of absolute.