mailcow - An open source mailserver suite.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
hMail Server - hMailServer is a free e-mail server for Microsoft Windows.
Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.
SmarterMail - SmarterMail is a next generation email management server that is offering several business collaboration and communication features as well.
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.