To answer this question you need to look further at the details of how LinkedIn works with content and the difference between items posted on a Company Page vs. content posted to a Group.
When an item is posted to a Company Page, LinkedIn does not provide any further "landing spot" to access or display just that content. It is simply displayed within the feed, and like a status entered on a personal profile, the content title links out to the article you may be referencing. There is no other way through the LinkedIn interface to see that content by-itself. The email link back to the content is similarly constrained. The best we can do is link the user to the Company page and let them find the content within the feed.
A LinkedIn group posting works differently. In this case, the posted item forms the beginning of a new thread or conversation. Through the LinkedIn interface, the titles of the group posts are clickable and the user can view each posting on its own isolated page and see the comments associated with it. In this case, the email can refer directly to this page and the "Join the Conversation" links lead the reader directly to the posting.
In either case, we encourage the reader to jump into the conversation, but the method of finding the actual posts unfortunately will vary since LinkedIn handles the situations differently.