Great post Jeff!

I remember one client of mine put an entire department into a writing/email class. It's amazing how bad some people are at written communications.

You covered a lot of the same writing guidelines as they did.

Some more specifics about sentences and paragraphs; sentences should be 12 to 18 words and no longer. Paragraphs should be 2-4 sentences and no longer.

It's unfortunate but, generally speaking, aiming for a 10th-grade reading level (in state indoctrination-camp speak) is the best way to reach a mass audience.