MailChimp - MailChimp is the best way to design, send, and share email newsletters.
SendOut - Affordable email marketing for bloggers and influencers
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.
Mailzak - Give a boost to your #EmailMarketing
Mailjet - All-in-one email service provider that provides maximum insight and deliverability results for both marketing and transactional emails.
Mailblast - Email marketing on a budget using Amazon SES