Asklayer - Get real answers from your customers with Asklayers surveys, quizzes, polls and more. Works on any website with zero code and includes enterprise level features such auto-segmentation, user tagging, branching, NPS & CSAT calculation.
Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.
Ask User - User surveys without stress
Mailman 3 - Dedicated Mailman 3 installation. Unlimited lists/configuration. Free subdomain at mailman3.com. Dedicated support for list admins.
Doorbell.io - Collect in-app user feedback. Available on websites, iOS, and Android.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.