Plunk
Open-source unified email platform.
Plunk unifies marketing, transactional, and broadcast email under one self-hostable open-source app. AGPL-3.0 license, EU hosting available. Developer-friendly API.
An agent stack treats email as a two-way primitive. Inbound has to arrive as structured JSON a tool call can consume, sends have to be safe to retry when a model loop repeats itself, and every action needs an audit trail. A provider without inbound parsing only solves half the problem.
Against inbound parsing into tool calls and model-generated sends that must not duplicate, Plunk covers webhook coverage, event stream, batch sending, and SDK breadth, and does not cover inbound parsing, idempotency keys, and multi-tenant support. Whether that gap matters depends on how central those are to the build.
- Inbound parsing: No
- Idempotency keys: No
- Webhooks: Yes
- Operating since: Not published
- Event stream: Yes
- Best published rate per 1,000: Tiers not published in comparable form
- Batch sending: Yes
- SDKs: node, python
- Multi-tenant: No
Self-hosted depends on your relay. Hosted plan inherits Plunks reputation.
Indie devs and EU-data teams who want self-hostable unified email.
- › Unified marketing + transactional
- › Self-hostable
- › Open source
- › Smaller community than Postal
- › No SMTP relay option
Features at a glance
| API | Yes |
| SMTP | No |
| SDKs | node, python |
| Webhooks | Yes |
| Templates | rich |
| React Email | No |
| Batch send | Yes |
| Scheduled send | Yes |
| Suppressions | Yes |
| Multi-tenant | No |
| Inbound parsing | No |
| Event stream | Yes |
| Idempotency keys | No |
| Dedicated IP | No |