FinancialForce HCM - FinancialForce.com provides cloud back-office applications for Salesforce CRM.
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
StarGarden HCM - StarGarden HCM is an integrated HR and Payroll software with workflow automation tools.
Mailman 3 - Dedicated Mailman 3 installation. Unlimited lists/configuration. Free subdomain at mailman3.com. Dedicated support for list admins.
Vibe HCM - Vibe HCM is a recruiting and employee engagement platform.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.