Don’t loose your audience. Start with the main thing, the core message. Begin all of your communications with the key message and stay on point.
If you remove the supporting evidence, the details and start with the key to the message, be it on e-mail, in a meeting or a presentation, then your audience will be engaged and likely to retain the information presented.
Journalists often use the method of the inverted pyramid and front-load their story, putting the essential and most attention-grabbing elements first. The least important information is left for the bottom. You can do the same when putting messaging together by keeping the main thing the main thing.