Collaboration History

I can’t seem to figure out how events such as e-mails are linked to contacts in order to be able to view a contact’s collaboration history. If outgoing e-mails and calendar entries are automatically linked, then I don’t have to be concerned with them. But what about incoming e-mails? Is there some command that would enable me to link them manually?

Subject: This is basically driven through bookmarks. Any document opened by the user is linked for collaboration history