# Cloudflare Email Service vs MailerSend

> MailerSend scores 69.5 (B) on agent readiness against Cloudflare Email Service's 67.3 (B), and leads in 2 of 7 scored categories. Cloudflare Email Service leads on schema & documentation, security & auth and transparency & trust. Both do email send. Category scores, facts…

- Canonical: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend
- Markdown: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.md (~2,750 tokens)
- Slim: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.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: 2026-10-08

MailerSend scores 69.5 (B) on agent readiness against Cloudflare Email Service's 67.3 (B), and leads in 2 of 7 scored categories. Cloudflare Email Service leads on schema & documentation, security & auth and transparency & trust. Both do email send.

- Cloudflare Email Service: grade B, 67.3/100, rank #212 of 722. Markdown https://www.anchorterminal.com/tools/cloudflare-email-service.md · JSON https://www.anchorterminal.com/api/v1/tools/cloudflare-email-service.json
- MailerSend: grade B, 69.5/100, rank #156 of 722. Markdown https://www.anchorterminal.com/tools/mailersend.md · JSON https://www.anchorterminal.com/api/v1/tools/mailersend.json

## Which one, for what

### Cloudflare Email Service (B)

Good for: Teams already on Cloudflare DNS and Workers that want transactional sending and inbound handling in one account at a low unit price.

Ahead on:
- Schema & documentation, 89 against 73
- Security & auth, 77 against 62
- Transparency & trust, 76 against 64

Watch for: Email Sending has been in public beta since 16 April 2026. Cloudflare's terms let it remove a beta service at any time, and no SLA was found

### MailerSend (B)

Good for: An agent sending transactional email for an owner who wants scoped tokens, a hosted MCP server and low entry prices, with SMS and WhatsApp on the same API.

Ahead on:
- Reliability, 95 against 51

Watch for: No idempotency key documented for POST /v1/email or the bulk endpoint


## Score by category

| Category | Weight | Cloudflare Email Service | MailerSend | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 51 | 95 | MailerSend +44 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 89 | 73 | Cloudflare Email Service +16 |
| Agent ergonomics | 13% (16.2 this run) | 72 | 69 | Cloudflare Email Service +3 |
| Security & auth | 14% (17.5 this run) | 77 | 62 | Cloudflare Email Service +15 |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 81 | 83 | MailerSend +2 |
| Transparency & trust | 7% (8.8 this run) | 76 | 64 | Cloudflare Email Service +12 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **67.3 · B** | **69.5 · B** | |

## Facts side by side

| Fact | Cloudflare Email Service | MailerSend |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Cloudflare | MailerSend, Inc. |
| Hosted endpoint | `https://api.cloudflare.com/client/v4` | `https://api.mailersend.com/v1` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Freemium |
| Price for email send | not published | $4 per month (plan) |
| x402 | no | no |
| Licence | Proprietary service under Cloudflare's Self-Serve Subscription Agreement and Developer Platform service-specific terms. The official `cloudflare` SDK on npm is Apache-2.0 | Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT |
| Tools exposed | none | 127 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-25 | 2026-09-29 |
| Terms last updated | 2025-09-12 | 2026-10-05 |
| Privacy policy last updated | no date given | 2026-09-17 |
| Customer content may train models | not found in the text | yes |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | yes | yes |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 3.8M npm/wk, 364k PyPI/wk | 175 stars, 128k npm/wk, 15k PyPI/wk |

## Verdicts

**Cloudflare Email Service.** Cloudflare API tokens can be limited to sending, given an expiry and restricted by IP address, and a public OpenAPI file covers 29 Email Sending operations. Sending is still in beta, with no SLA, no idempotency key and no published daily quota, and it needs a domain on Cloudflare DNS and the Workers Paid plan.

**MailerSend.** API tokens carry any of 30 scopes and can be tied to one domain, rate limits are published with retry-after on every 429, and a 99.5 per cent SLA starts on the $35 Starter plan. Sends take no idempotency key, the Free plan allows 100 API requests a day, and the terms permit changes without notice.

## Before you call either

### Cloudflare Email Service

1. POST to `https://api.cloudflare.com/client/v4/accounts/{account_id}/email/sending/send` with `Authorization: Bearer <token>`. The body needs `to`, `from`, `subject` and one of `html` or `text`
2. Don't retry a timed-out send blindly. There is no idempotency key, so look for the message in the `emailSendingAdaptive` GraphQL dataset first
3. On 429 (code 10004) wait for the `retry-after` header. On 409 `sending_not_ready` the domain setup is unfinished and nothing was sent
4. Read `result.delivered`, `result.queued` and `result.permanent_bounces` in the response. A 200 does not mean every recipient was accepted
5. Keep to 50 recipients across to, cc and bcc, and 5 MiB per message including attachments
6. For SMTP use `smtp.mx.cloudflare.net` on port 465 with implicit TLS, username `api_token` and the API token as password. Port 587 is not supported
7. By default one suppressed recipient fails the whole send. Turn on Drop suppressed recipients for the domain to send to the rest

### MailerSend

1. Send `Authorization: Bearer <token>` to https://api.mailersend.com/v1 and ask for a token with only the scopes the task needs, such as `email_full` and `activity_read`
2. Read the message id from the `x-message-id` response header. POST /v1/email answers 202 with an empty body
3. Check for a sent message before retrying a send. No idempotency key exists, so a blind retry can deliver twice
4. On a 429 wait the seconds in `retry-after`. Call GET /v1/api-quota, which isn't counted, to see the daily quota left
5. Use POST /v1/bulk-email for batches of up to 500 emails. It isn't on the Free plan and takes 10 to 60 requests a minute by plan

## Questions

### Which is better for AI agents, Cloudflare Email Service or MailerSend?

MailerSend scores 69.5 (B) on agent readiness against Cloudflare Email Service's 67.3 (B), and leads in 2 of 7 scored categories. Cloudflare Email Service leads on schema & documentation, security & auth and transparency & trust.

### Do Cloudflare Email Service and MailerSend need an API key?

Cloudflare Email Service needs an API key. MailerSend takes an API key or an OAuth sign-in.

### Can an agent call Cloudflare Email Service and MailerSend without installing anything?

Yes. Cloudflare Email Service has a hosted endpoint at https://api.cloudflare.com/client/v4 and MailerSend at https://api.mailersend.com/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.json, and with the fewest tokens: https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "cloudflare-email-service", "b": "mailersend"}`. From a terminal: `anchor compare cloudflare-email-service mailersend`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/cloudflare-email-service.json and https://www.anchorterminal.com/api/v1/tools/mailersend.json

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