First: presenting donors with a Table of Contents as a substitute for genuine content.
It's worth noting that creating marketing emails full of links (regardless of how compelling those links are) doubles the amount of work for staff—because those links must go to web pages that often need to be created and maintained.
In my experience, the best approach is a middle one: provide your donors with real content—just make it short. (A paragraph or two at most, 2 or 3 stories at most.)