A goal for email newsletters is to make your newsletter stick out and to have stickiness (read over and again). Here are some guidelines to keep in mind for your next email:

Make it Useful.
People are barraged with emails... give them a reason to pause and read yours. Give them a reason to save it and open it again. Give them some insight that can impact their life and/or business.

Make it Interesting.
No one said news had to be boring... e-newletters with personal anecdotes, conversational language and the occasional joke will keep your readers involved. The longer they read the more they will read.

Make it Simple.
Like anything on the web - it shouldn't be lengthy. Let the newsletter be a teaser and refer them to a page if they want more. Try to keep your newsletter within a theme or one concept. The easier it is to read, the easier it is to remember.

Make it Authentic.
Anything coming from your company, reflects the voice of your company and it's unique personality. Your e-newsletter should do the same - you don't have to cover it up "professionalism" if that's not the culture of your business.