There are many email marketing services out there to choose from, but they can all be put into one of two categories: basic and advanced. Basic email marketing services do everything you expect a typical email marketing tool to do (e.g., send emails, track results, generate sign-up forms). Advanced email marketing services do more than the basics by creating behavioral-based emails, split-testing autoresponders, etc.
Jeremy Reeves at The Daily Egg reviews four basic services (MailChimp, Aweber, iContact and Constant Contact) and two advanced services (Infusionsoft and Office Autopilot), discussing the pros and cons of each.
Of course, the best software available won’t help if marketers don’t implement best practices in their email marketing campaigns.