Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.

UpToDate - UpToDate, the evidence-based clinical decision support resource from Wolters Kluwer, is trusted at the point of care by clinicians worldwide.

Mailman - Mailman is free software for managing electronic mail discussion and e-newsletter lists.

WellApp - WellApp provides you a simple and easy path to communicate with patients and doctors.

Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES

MobileDDx - MobileDDx is an absolutely free application that is designed to locate diseases, symptoms, and medication in a very advanced manner.