Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Mailblast - Email marketing on a budget using Amazon SES
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
GetResponse - Email marketing from GetResponse. Send email newsletters, campaigns, online surveys and follow-up autoresponders. Simple, easy interface. FREE sign up.
Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
TinyLetter - Start writing your own newsletter instantly.