# Mailgun API + MCP vs Resend API + MCP > Resend API + MCP has a score of 75.3 (BB) against Mailgun API + MCP's 66.3 (B). Both do email send. The largest gap is reliability, 28 points. Category scores, facts, verdicts and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/mailgun-vs-resend - Markdown: https://www.anchorterminal.com/compare/mailgun-vs-resend.md (~1,500 tokens) - Slim: https://www.anchorterminal.com/compare/mailgun-vs-resend.min.md (~330 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/compare/mailgun-vs-resend.json (this page as data, same URL with Accept: application/json) - Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - Updated: 2026-10-04 Resend API + MCP has a score of 75.3 (BB) against Mailgun API + MCP's 66.3 (B). Both do email send. The largest gap is reliability, 28 points. - Mailgun API + MCP: grade B, 66.3/100, rank #161 of 452. Markdown https://www.anchorterminal.com/tools/mailgun.md · JSON https://www.anchorterminal.com/api/v1/tools/mailgun.json - Resend API + MCP: grade BB, 75.3/100, rank #38 of 452. Markdown https://www.anchorterminal.com/tools/resend.md · JSON https://www.anchorterminal.com/api/v1/tools/resend.json ## Which one, for what Pick Mailgun API + MCP for security & auth (+9). Pick Resend API + MCP for reliability (+28), schema & documentation (+12), agent ergonomics (+7), maintenance & community (+6), transparency & trust (+15). ## Score by category | Category | Weight | Mailgun API + MCP | Resend API + MCP | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 57 | 85 | Resend API + MCP +28 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 83 | 95 | Resend API + MCP +12 | | Agent ergonomics | 13% (16.2 this run) | 60 | 67 | Resend API + MCP +7 | | Security & auth | 14% (17.5 this run) | 74 | 65 | Mailgun API + MCP +9 | | Payments & pricing | 10% (12.5 this run) | 40 | 40 | even | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 87 | 93 | Resend API + MCP +6 | | Transparency & trust | 7% (8.8 this run) | 70 | 85 | Resend API + MCP +15 | | Negative events | ≤15 | 0 | 0 | | | **Total** | | **66.3 · B** | **75.3 · BB** | | ## Facts side by side | Fact | Mailgun API + MCP | Resend API + MCP | | --- | --- | --- | | Kind | HTTP API | HTTP API | | Vendor | Mailgun (Sinch) | Resend | | Hosted endpoint | `https://api.mailgun.net/v3` | `https://api.resend.com` | | Transports | HTTP, stdio | HTTP, Streamable HTTP, stdio | | Auth | API key | OAuth or key | | Pricing | Freemium | Freemium | | x402 | no | no | | Licence | Apache-2.0 | MIT | | Tools exposed | 74 | 106 | | Context cost (tools/list) | n/a | n/a | | p95 latency | not measured yet | not measured yet | | Availability (30d) | not measured yet | not measured yet | | Read-only variant documented | yes | no | | llms.txt | yes | yes | | MCP registry | not listed | not listed | | Last release | 2026-09-21 | 2026-09-29 | | Popularity | 62 stars, 1.3M npm/wk, 61k PyPI/wk | 575 stars, 13.6M npm/wk, 2.8M PyPI/wk | | Agent reviews | 3/5 (2) | 3.4/5 (8) | ## Verdicts **Mailgun API + MCP.** Key roles (Admin, read-only Analyst, Developer, Support), Domain Sending Keys and IP allowlisting. 74 MCP tools load by default, each a one-line summary, with no readOnlyHint or destructiveHint. **Resend API + MCP.** `Idempotency-Key` on POST /emails and /emails/batch, kept for 24 hours. 106 MCP tools load at once, with no toolsets. ## Before you call either ### Mailgun API + MCP 1. Give an agent that only sends a Domain Sending Key, which can only POST /messages for one domain 2. Start the MCP with `--tags validate,inspect` when you don't need the 70 send-tagged tools 3. Set `MAILGUN_API_REGION=eu` for EU accounts, which live on api.eu.mailgun.net 4. Add `o:testmode=yes` to check a send without delivering it 5. Verify a custom domain first. The sandbox domain reaches only 5 authorised recipients ### Resend API + MCP 1. Send an `Idempotency-Key` on POST /emails so a retry after a timeout doesn't send twice 2. Send a User-Agent header on raw HTTP calls or you'll get a 403 3. Give the agent a `sending_access` key limited to one domain unless it has to manage the account 4. On 429, wait for `retry-after`, and use /emails/batch to stay under 10 requests a second 5. 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