# MailPace (slim)

> MailPace is a UK transactional email service, formerly OhMySMTP, hosted in the EU. It sends mail through an HTTPS API or SMTP, turns inbound mail into webhooks and has a Domains and Email Status API.

- Full: https://www.anchorterminal.com/tools/mailpace.md (~6,650 tokens) · this version ~1,530 tokens · JSON https://www.anchorterminal.com/tools/mailpace.json · canonical https://www.anchorterminal.com/tools/mailpace
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07 · pricing https://www.anchorterminal.com/tools/mailpace#pricing · reviews https://www.anchorterminal.com/tools/mailpace#reviews
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

**C · 58.4/100 · rank #750 of 1486 · #17 in Email delivery APIs · not agent-ready · confidence medium**


Assessment: A small transactional sender with idempotent sends, signed webhooks, a 99% availability promise in its terms and a public Upptime status record. There is no OpenAPI spec, no published rate limit, no llms.txt, and its MCP server was rewritten on 4 November 2026 but isn't on npm or in the MCP registry yet.

## Facts

- Kind: HTTP API · vendor: OhMySMTP Ltd · category: Email delivery APIs · legal entity: OhMySMTP Ltd · provenance 81/100
- Local only (HTTP): npm `@mailpace/mailpace.js`
- Auth: API key · pricing: Paid · x402: no · licence: unknown
- Benchmark probes: not run yet, so Performance is pending
- Vendor status page: not read, no machine-readable status found (2026-11-07 04:48 UTC)
- Surface listed: The HTTPS API at app.mailpace.com/api/v1 (send, Domains API, Email Status API), SMTP and inbound webhooks, read from the docs repository, mailpace.com, the landing and status repositories and the MCP server source on 6 November 2026. No account was made
- Limits: Up to 50 recipients in the To field, no batch endpoint, 30 MB total message size per the send reference (the home page says 25 MB). Rate limits unpublished
- Retention: Emails shown in the dashboard for 30 days, deleted from backups 7 days later, 37 days at most, per the DPA
- MCP server: mailpace-mcp 2.0.0, stdio, MIT, 12 tools (send, email status, domains and domain tokens), rewritten 4 November 2026. Its README says it will be published to npm and the official MCP registry as com.mailpace/mailpace-mcp
- Hosting: Freethought (EU-hosted application servers and databases), Hetzner backups in Germany, AppSignal in Amsterdam, Paddle and Tutanota, per the privacy policy of 30 August 2026
- Previous name: OhMySMTP until January 2022; the company is still OhMySMTP Ltd
- Prices: Scaling plan $10 per month (plan); Emails beyond 10,000 $1 per 1,000 emails

- Scores: Reliability 70, Performance pending, Schema & documentation 54, Agent ergonomics 71, Security & auth 50, Payments & pricing 25, Task success pending, Maintenance & community 65, Transparency & trust 75 · total over the 7 assessed categories
- Why: Reliability, Graded with the hosted lines. · Schema & documentation, No OpenAPI or other machine-readable contract for the HTTPS API. · Agent ergonomics, Responses are small, the send returns an id and status and Email Status returns one email (18 of 25). · Security & auth, Per-domain server tokens that can only send from and read status for their domain, and an organisation token that creates, renames and revok… · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, Email Status API documented on 22 October 2026, and the MCP server rewritten as 2.0.0 on 4 November 2026, two days before this check (30). · Transparency & trust, Closed hosted service under terms that name OhMySMTP Ltd with its company number.
- Sources: 11, open questions: 4, both in the full twin
- Capabilities: email.send, email.inbound, email.domains, email.analytics
- JSON: https://www.anchorterminal.com/api/v1/tools/mailpace.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/mailpace.svg` or a link to https://www.anchorterminal.com/tools/mailpace from a page on mailpace.com or one of its subdomains, or the README at the root of github.com/mailpace/mailpace-mcp, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.
- Support: support@mailpace.com; https://docs.mailpace.com/; https://status.mailpace.com; more in the full twin

## Before you call it

1. Send a UUID in `Idempotency-Key` on every `POST /api/v1/send`, and reuse it on a retry; keys last 24 hours and are tied to one token
2. Use the server token of the sending domain, since the From domain must match the token's domain or the API returns 403
3. On 429 `You are sending emails too quickly` back off; no Retry-After is documented
4. Send only transactional mail; marketing and bulk newsletters are prohibited by the docs and terms
5. Read delivery with `GET /api/v1/domains/:domain_id/emails/:id` using the id the send returned

## Connect

```bash
curl https://app.mailpace.com/api/v1/send -X POST -H "Accept: application/json" -H "Content-Type: application/json" -H "MailPace-Server-Token: $MAILPACE_TOKEN" -H "Idempotency-Key: $(uuidgen)" -d '{"from":"you@yourdomain.com","to":"person@example.com","subject":"Hello","textbody":"Hello"}'
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/mailpace

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Resend API + MCP | A | 78.1 | email.send, email.inbound, email.domains, email.analytics | https://www.anchorterminal.com/tools/resend.min.md |
| AhaSend API + MCP | BB | 75.4 | email.send, email.domains, email.analytics, email.inbound | https://www.anchorterminal.com/tools/ahasend.min.md |
| Amazon SES | BB | 73.6 | email.send, email.inbound, email.domains, email.analytics | https://www.anchorterminal.com/tools/amazon-ses.min.md |
| AgentMail API + MCP | BB | 72.8 | email.send, email.inbound, email.domains, email.analytics | https://www.anchorterminal.com/tools/agentmail.min.md |
| MailerSend | BB | 71.4 | email.send, email.inbound, email.domains, email.analytics | https://www.anchorterminal.com/tools/mailersend.min.md |


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