Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Bigtent - BigTent is a web-based organization and communication portal for groups.
Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
Nabble - Nabble is a forum software that are embeddable and fully customizable with scripting language.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.