sending links to confidential documents in Outlook

New Adobe user.  Linked to my outlook for work.  Should I be concerned about attaching confidential pdf files as an Adobe Link?  And is that the default if I say never prompt while attaching?  It would seem not, since there is a choice to Automatically send attachments using Adobe Document Cloud, but I want to be sure.  What is the benefit of using Adobe Cloud?  Can I send really large files that way, when Outlook minimizes the total megabytes I can attach?