Kill the Newsletter! - Convert newsletters into RSS feeds
Mailtrain - Self-hosted open-source Mailchimp clone
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Reeder - Reeder is an RSS reader and client for multiple services.
Free Twitter RSS Feed Generator - Convert Twitter lists, hashtags & searches into RSS feeds
Supscrib for Business - Build engaging newsletter & save on email costs