Constant Contact is the clear winner when it comes to list management, rate of e-mail deliverability, and customer support. They’ve also got more options for importing contacts and a greater variety of ready-to-use e-mail templates. However, Constant Contact lacks A/B testing functionality and advanced automation features, which may be a deal breaker for professional marketers. They’re also priced a bit higher compared to other options in the market, but they do offer a 60-day free trial capped at 100 unique contacts.