People read email differently than they read a brochure or a newspaper. If someone is enticed by the subject line (or very loyal to your organization) they may open your email and skim it, not really read it. Lots of text makes skimming difficult.
I come across emails from arts organizations that are laden with text and my eyes glaze over. I see full quotes from reviews and long explanations of programming. Emails are not brochures. Your emails should be primarily driven by graphics. The less text the better. Next time you write out an email try this exercise: Cut the text you wrote in half and then cut it in half again. This is not easy but I bet there is lots of fat you can trim and still tell your story. Use an image or graphic to tell the story instead.
The point of the email is to drive users to click through to where they can get more information. Provide just enough information to entice them to click. Think bullet points and short sentences, not paragraphs.
Finally if you have a 20% open rate, to the other 80% of people your email is your subject line. You can still get your message across to those 80% of people if your subject line tells the story. "Season Opens tomorrow" "Student Tickets Now on Sale" etc.
Here are two great emails. The subject line tells the story, they are image driven, have only the absolute necessary amount of text, and they have a strong call to action.
Have some great emails that meet the criteria above? Please send them in and I will post them.