HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Mailman 3 - Dedicated Mailman 3 installation. Unlimited lists/configuration. Free subdomain at mailman3.com. Dedicated support for list admins.
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.
Pardot - Salesforce B2B marketing automation