Writing long email messages is a disservice to your audience and to yourself.

Your audience does not have time for long, they will at best skim through the message and forget about it the moment they close it (hopefully they will not decide to follow up with another message). You will fail to get through to them, your idea will be diminished, your questions and concerns drowned in adjectives and adverbs, and you will inevitably feel the urge to explain yourself, to add more, to elaborate, in short to add to the confusion.

The time you take to make your message crisp is time well spent.