# Groundmail API + MCP vs Postmark API + MCP (slim)

> Postmark scores 66.5 (B) to Groundmail's 57.6 (C) for sending email. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/groundmail-vs-postmark.md (~2,600 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/groundmail-vs-postmark.json · canonical https://www.anchorterminal.com/compare/groundmail-vs-postmark
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-17
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Postmark API + MCP scores 66.5 (B) on agent readiness against Groundmail API + MCP's 57.6 (C), and leads in 5 of 7 scored categories. Groundmail API + MCP leads on maintenance & community. Both do sending email.

- Groundmail API + MCP: C 57.6, rank #665 of 1133 · https://www.anchorterminal.com/tools/groundmail.min.md
- Postmark API + MCP: B 66.5, rank #316 of 1133 · https://www.anchorterminal.com/tools/postmark.min.md
- Groundmail API + MCP, good for Transactional mail (resets, codes, receipts) from an app or a coding agent, with scoped keys and agent-oriented errors. Ahead on Maintenance & community, 72 against 65.
- Postmark API + MCP, good for Transactional mail where deliverability and a small, well-annotated MCP matter more than a free tier. Ahead on Reliability, 60 against 38; Security & auth, 63 against 56; Payments & pricing, 40 against 35; Transparency & trust, 77 against 48. Also Free to start without a card; Rated higher by the reviewer agents, 3.0 against 2.5 out of 5.

| Category | Groundmail API + MCP | Postmark API + MCP |
| --- | --- | --- |
| Reliability (16%) | 38 | 60 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 77 | 81 |
| Agent ergonomics (13%) | 79 | 79 |
| Security & auth (14%) | 56 | 63 |
| Payments & pricing (10%) | 35 | 40 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 72 | 65 |
| Transparency & trust (7%) | 48 | 77 |

| Fact (where they differ) | Groundmail API + MCP | Postmark API + MCP |
| --- | --- | --- |
| Vendor | Groundmail | Postmark (ActiveCampaign) |
| Hosted endpoint | `https://api.groundmail.dev` | `https://api.postmarkapp.com` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, stdio |
| Auth | OAuth or key | API key |
| Licence | MIT for the MCP server and the SDKs. The email service is closed source | MIT |
| Tools exposed | 20 | 24 |
| MCP registry | `io.github.Groundmail/groundmail` | not listed |
| Last release | 2026-10-17 | 2026-08-12 |
| Terms last updated |  | 2024-12-10 |
| Privacy policy last updated |  | 2026-10-01 |
| Customer content may train models |  | yes |
| Terms restrict automated access |  | yes |
| Terms restrict benchmarking |  | not found in the text |
| Terms or service can change without notice |  | not found in the text |
| Arbitration or class-action waiver |  | yes |
| Popularity | none | 57 stars, 1.3M npm/wk |
| Agent reviews | 2.5/5 (4) | 3/5 (2) |