MessageOne - MessageOne offers email management solutions such as EMS and AlertFind for archiving, e-discovery, security and notification services.
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Vade Secure - Email security to protect against email-borne phishing, spear phishing, malware, and ransomware. Email security and management based on artificial intelligence.
Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
Clean Email - Clean Email is an online service that empowers you to take control of your mailbox.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.