Make it easy to quote. Power email users will quote and respond to specific sections or sentences of your message. You can facilitate this by keeping your paragraphs short, making them easy to slice and dice.
Skip the overture. If you’re writing to a busy person with an actual question or request, resist the desire to swoon for 2,000 characters. Either write a fan letter or a useful email, but mixing them can seem tacky and disingenuous.
What’s the action here? If your message includes any kind of request—whether for a meeting, a progress update, a pony ride, or what have you—put that request near the top of the message and clearly state when you will need it. Do not, under any circumstances, assume that your overwhelmed recipient will take the time to sift through your purple prose for clues about what they’re supposed to be doing for you.