Notifuse is an open-source & modern emailing platform
...The system includes a drag-and-drop MJML email builder, webhook integrations, and multi-provider support for SMTP services and cloud providers, while also tracking opens, clicks, and delivery performance in real time.
...ESMTP server implementing RFC5321. Support for SMTP AUTH (RFC4954) and PIPELINING (RFC2920). Web interface to view messages (plain text, HTML or source). Supports RFC2047 encoded headers. Real-time updates using EventSource. Release messages to real SMTP servers. Chaos Monkey for failure testing. HTTP API to list, retrieve and delete messages. See APIv1 and APIv2 documentation for more information. HTTP basic authentication for MailHog UI and API. Multipart MIME support. Download individual MIME parts. In-memory message storage. ...