* Use a few bullet points to put attention on the main points you want to convey.
* Without going overboard, use a tasteful amount of graphic design (bolding one key sentence or whatever).
* Break up a giant nuanced email into sections.
* If something is critical, make it visual: a picture, explainer video, or an infographic can be really useful for something key.
This is harder than it looks. A quote attributed to Mark Twain is "I didn't have time to write a short letter, so I wrote a long one instead." It's a lot easier to go overboard than to distill what needs to be conveyed into the core elements.
1) Assume no prior knowledge of a situation.
2) Provide some context for intent, objectives etc..
3) Greatly simplify the thrust of the message and initially provided only the most highly relevant details.
If you do that - then 'everything else is a detail' - meaning, if someone has a basic understanding of what the situation is, they can go into detail as needed.
If context is not provided, people have no idea what is going on and their professionalism, conscientiousness and curiosity is wasted.
I like the AMZN approach but I'll gather it could be done in a different way.