Sessy

Amazon SES is cheap, reliable and almost silent about what happens after you press send. That silence is why so many teams end up paying a transactional email provider that is largely an SES wrapper with a nicer interface. Sessy is the open source version of that interface, sitting on top of raw SES.

It is a Rails application, most easily run as a Docker image with a secret key base and a storage volume, with deployment docs for Kamal and Dokku if you want to run a fork. Background work goes through Solid Queue, and a dashboard at the jobs path lets you watch queues, retry failures and inspect recurring tasks.

What you get beyond the send itself is visibility and programmatic access.

• Delivery events: deliveries, bounces, complaints, opens and clicks presented in one interface.
• MCP server: a read-only endpoint lets coding agents search events, inspect a message timeline with bounce diagnostics and pull aggregate stats.
• API keys: created in the web UI, and the MCP endpoint authenticates with those keys only, ignoring HTTP basic auth entirely.
• CDN caveat: Cloudflare bot protection blocks MCP clients unless you exempt that path.
• Hosted code in the open: the managed version's engine lives in this repository, and the test suite verifies the open source build behaves identically without it.

Guides cover configuring SES itself and hardening an install for security and deliverability. The license is O'Saasy, except where a subdirectory says otherwise.