Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
Mailtrain - Self-hosted open-source Mailchimp clone
Revue - The easiest way to create and send a curated newsletter
Kill the Newsletter! - Convert newsletters into RSS feeds
Really Good Emails - A large collection of good product email design.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.