Plunk

Spec sheet

Product

Plunk is an open-source email platform for transactional email, marketing campaigns, and automated workflows against one contact list.Read 8 Oct 2026 · useplunk.com

Free plan

YesRead 23 Sep 2026 · useplunk.com

Integrations

Plunk offers a REST API, SDKs including Node.js and Python, SMTP support, webhooks, and an MCP server that works with MCP clients such as Claude Code, Claude Desktop, and Cursor.Read 8 Oct 2026 · useplunk.com

Support

The maker invites customer feedback and lists a Discord community on its site.Read 8 Oct 2026 · useplunk.com

Campaigns and analytics

Campaigns can target a full list or segment, with tracking for opens, clicks, bounces, and unsubscribes.Read 8 Oct 2026 · useplunk.com

Compliance scope

The DPA applies to Plunk's hosted service and says self-hosted deployments are not covered by it.Read 8 Oct 2026 · useplunk.com

Data residency

The DPA states that primary data storage is in the EU/EEA on Hetzner infrastructure, while email delivery may transit non-EU regions through AWS SES.Read 8 Oct 2026 · useplunk.com

Data security

The DPA describes HTTPS-only API access using TLS 1.2+, encrypted database connections, limited-expiry authentication tokens, rate limiting, and project-level data isolation.Read 8 Oct 2026 · useplunk.com

Inbound email

One MX record enables inbound email at the domain, with parsed message content delivered to an endpoint as JSON and inbound messages able to trigger workflows.Read 8 Oct 2026 · useplunk.com

Notable limit

Rendered email bodies are deleted after 90 days, while stats and activity are kept.Read 8 Oct 2026 · useplunk.com

Self-hosting

The AGPL-3.0 licensed platform can be deployed on the customer's infrastructure using Docker Compose.Read 8 Oct 2026 · useplunk.com

Transactional email

It supports API and SMTP delivery for receipts, password resets, and other event-driven email.Read 8 Oct 2026 · useplunk.com

Who it is for

The maker describes Plunk as an independent SaaS run by a person, and its editor page describes use by developers, marketers, and teams sharing templates.Read 8 Oct 2026 · useplunk.com

Workflows

Workflows start from product events and can include delays, conditions, branches, email steps, and outbound webhooks.Read 8 Oct 2026 · useplunk.com

Plans and prices

Every Plunk plan and price →

Where Specifiction places it

• Transactional email services#23 of 418.1
• Email APIs#23 of 317.6
• Transactional Email Software#31 of 417.8