toolgrep / Email & messaging / Plunk
Alternatives to Plunk
Plunk: Open-source transactional email platform. 8 products similar to Plunk, compared on pricing, free tier, API, MCP server, SDK and open source. 8 of 8 have a free tier, 8 of 8 have an API, 5 of 8 offer an MCP server, 1 of 8 is open source.
- Knock
Customer engagement infrastructure for product, marketing, and transactional messaging
- Reloop
Open-source email API and infrastructure for developers: transactional email, SMTP relay, campaigns, webhooks, and agent inboxes.
- Postmark
Transactional and bulk email delivery service with REST API and SMTP support
- Anypost
Transactional and broadcast email service
- Mailtrap
Email delivery platform for developer and product teams: Email API/SMTP sending, email testing sandbox, and email marketing.
- Mailjet
Email marketing software and email API for marketing and transactional email
- Buttondown
Newsletter software for writers, creators, and developers
- Unitpost
Email and SMS sending platform for developers, with API, SDKs, SMTP, and an MCP server for AI agents.
Side by side
| Product | Pricing | Free tier | API | MCP server | SDK | Open source |
|---|---|---|---|---|---|---|
| Plunk | Freemium | yes | yes | yes | no | yes |
| Knock | Freemium · from $0 | yes | yes | yes | yes | no |
| Reloop | Freemium · from $0 | yes | yes | yes | yes | yes |
| Postmark | Freemium · from $15.00/mo | yes | yes | no | yes | no |
| Anypost | Freemium · from $0 (Free: 3,000 emails/month); paid plans from $20/mo | yes | yes | no | yes | no |
| Mailtrap | Freemium · from $15 | yes | yes | yes | yes | no |
| Mailjet | Freemium | yes | yes | yes | yes | no |
| Buttondown | Freemium | yes | yes | no | yes | no |
| Unitpost | Freemium · from $0/mo (Free, 5k emails/mo); paid plans from $10/mo | yes | yes | yes | yes | no |
Facts come from each product's own website, or from its verified owner when they have edited the listing. Each product page shows when it was last verified and how it was extracted. Similarity comes from the products' descriptions.
API
curl https://toolgrep.com/api/products/plunk/alternatives