Postmark vs Resend for AI agents
Resend is more ready for AI agents than Postmark: 89 vs 83 out of 100. Resend is ahead on a remote MCP server, an OpenAPI spec and OAuth self-registration. Postmark is ahead on labelled form fields and no card to start.
What an agent finds
| Postmark | Resend | |
|---|---|---|
| Score | 83/100 | 89/100 |
| Blocks AI agents | No | No |
| robots.txt disallows | No AI bots | No AI bots |
| llms.txt | At the root | At the root |
| Remote MCP server | none found | mcp.resend.com/mcp |
| Docs MCP server | none found | none found |
| OpenAPI spec | none found | resend.com/openapi.yaml |
| Developer docs | postmarkapp.com/developer | resend.com/docs/introduction.md |
| Public pricing | postmarkapp.com/pricing | resend.com/pricing |
| Self-serve sign-up | Yes, opens for agents | Yes, opens for agents |
Check by check
60 core points every site needs, plus 40 split between letting an agent sign a team up and connecting through the API. Sign-up and API checks count half each.
| Check | Points | Postmark | Resend |
|---|---|---|---|
| Core | 54 | 51 | |
| Agents get the real page, not a bot wall | 12 | ✓ | ✓ |
| robots.txt lets user-triggered agents in | 6 | ✓ | ✓ |
| Answer-engine crawlers are allowed | 4 | ✓ | ✓ |
| Content is in the raw HTML | 6 | ✓ | ✓ |
| Semantic HTML (main, nav, header) | 4 | · | · |
| Icon buttons and links have names | 3 | ✓ | ✓ |
| Form fields have labels | 3 | ✓ | · |
| Images have alt text | 3 | ✓ | ✓ |
| The page has an H1 | 2 | ✓ | ✓ |
| Structured data (JSON-LD) | 5 | ✓ | ✓ |
| Meta description and Open Graph tags | 3 | ✓ | ✓ |
| sitemap.xml | 3 | ✓ | ✓ |
| llms.txt | 4 | ✓ | ✓ |
| Dates show the content is fresh | 2 | · | · |
| Sign-up | 20 | 18 | |
| Public pricing page | 5 | ✓ | ✓ |
| A self-serve sign-up link | 4 | ✓ | ✓ |
| Sign-up page opens for agents | 3 | ✓ | ✓ |
| A free plan or trial | 3 | ✓ | ✓ |
| No card needed to start | 2 | ✓ | · |
| SoftwareApplication data | 3 | ✓ | ✓ |
| API | 8.5 | 20 | |
| OpenAPI spec | 3.5 | · | ✓ |
| Remote MCP server | 4 | · | ✓ |
| Docs as markdown | 2.5 | ✓ | ✓ |
| Self-serve API keys | 3 | ✓ | ✓ |
| OAuth client self-registration | 2.5 | · | ✓ |
| OAuth discovery metadata | 1.5 | · | ✓ |
| SDKs and a CLI | 1.5 | ✓ | ✓ |
| Free tier or test keys | 1.5 | ✓ | ✓ |
Automated, read-only scan of each homepage, robots.txt, llms.txt, docs, OpenAPI paths and MCP endpoints on 3 Nov 2026. How scoring works.
Check them again today
Sites change. Run the live scan for the current result, or check your own site.
Questions
Is Postmark or Resend better for AI agents?
Resend is more ready for AI agents than Postmark: 89 vs 83 out of 100. Resend is ahead on a remote MCP server, an OpenAPI spec and OAuth self-registration. Postmark is ahead on labelled form fields and no card to start. Scores are from our scan on 3 Nov 2026.
Does Postmark have an MCP server?
Not one we could find. On 3 Nov 2026 our scan found no remote MCP server for Postmark at the usual addresses (mcp.postmarkapp.com/mcp, api.postmarkapp.com/mcp, the docs host, or any MCP URL linked from its homepage or llms.txt).
Does Resend have an MCP server?
Yes. Our scan reached a remote MCP server at https://mcp.resend.com/mcp on 3 Nov 2026.
Does Postmark block AI agents?
No. Postmark served its homepage to an AI user-agent and its robots.txt doesn't disallow any of the AI crawlers we check.
Does Resend block AI agents?
No. Resend served its homepage to an AI user-agent and its robots.txt doesn't disallow any of the AI crawlers we check.