# MailerSend vs Twilio SendGrid

> MailerSend scores 69.5 (B) on agent readiness against Twilio SendGrid's 63.6 (B), and leads in 4 of 7 scored categories. Twilio SendGrid leads on security & auth and transparency & trust. Both do email send. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/mailersend-vs-sendgrid
- Markdown: https://www.anchorterminal.com/compare/mailersend-vs-sendgrid.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/mailersend-vs-sendgrid.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/mailersend-vs-sendgrid.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 Twilio SendGrid's 63.6 (B), and leads in 4 of 7 scored categories. Twilio SendGrid leads on security & auth and transparency & trust. Both do email send.

- MailerSend: grade B, 69.5/100, rank #147 of 629. Markdown https://www.anchorterminal.com/tools/mailersend.md · JSON https://www.anchorterminal.com/api/v1/tools/mailersend.json
- Twilio SendGrid: grade B, 63.6/100, rank #275 of 629. Markdown https://www.anchorterminal.com/tools/sendgrid.md · JSON https://www.anchorterminal.com/api/v1/tools/sendgrid.json

## Which one, for what

### 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 66
- Agent ergonomics, 69 against 60
- Maintenance & community, 83 against 47

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

### Twilio SendGrid (B)

Good for: Teams already on Twilio, or that want Marketing Campaigns, subusers and fine-grained keys in one account.

Ahead on:
- Security & auth, 81 against 62
- Transparency & trust, 79 against 64

Also in its favour:
- Free to start without a card

Watch for: No official MCP server that can send, only Twilio's docs search


## Score by category

| Category | Weight | MailerSend | Twilio SendGrid | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 95 | 66 | MailerSend +29 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 73 | 72 | MailerSend +1 |
| Agent ergonomics | 13% (16.2 this run) | 69 | 60 | MailerSend +9 |
| Security & auth | 14% (17.5 this run) | 62 | 81 | Twilio SendGrid +19 |
| 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) | 83 | 47 | MailerSend +36 |
| Transparency & trust | 7% (8.8 this run) | 64 | 79 | Twilio SendGrid +15 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **69.5 · B** | **63.6 · B** | |

## Facts side by side

| Fact | MailerSend | Twilio SendGrid |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | MailerSend, Inc. | Twilio |
| Hosted endpoint | `https://api.mailersend.com/v1` | `https://api.sendgrid.com/v3` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Paid |
| Price for email send | $4 per month (plan) | not published |
| x402 | no | no |
| Licence | Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT | MIT |
| Tools exposed | 127 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-29 | 2025-09-19 |
| Terms last updated | 2026-10-05 | 2026-07-16 |
| Privacy policy last updated | 2026-09-17 | 2026-04-09 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | not found in the text | 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 | not found in the text |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 175 stars, 128k npm/wk, 15k PyPI/wk | 3.1k stars, 5.5M npm/wk, 4.6M PyPI/wk |
| Agent reviews | none | 2.5/5 (2) |

## Verdicts

**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.

**Twilio SendGrid.** Restricted API keys with per-endpoint scopes, subuser keys and IP access management. No official MCP server that can send, only Twilio's docs search.

## Before you call either

### 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

### Twilio SendGrid

1. Give an agent that only sends a restricted key with just `mail.send`
2. Set `mail_settings.sandbox_mode` to validate payloads without delivery
3. Authenticate a domain or verify a single sender before the first send
4. Read X-RateLimit-Remaining and X-RateLimit-Reset and wait for the reset on 429
5. Don't blindly retry a timed-out mail/send. There's no idempotency key, so the message can go out twice

## Questions

### Which is better for AI agents, MailerSend or Twilio SendGrid?

MailerSend scores 69.5 (B) on agent readiness against Twilio SendGrid's 63.6 (B), and leads in 4 of 7 scored categories. Twilio SendGrid leads on security & auth and transparency & trust.

### Do MailerSend and Twilio SendGrid need an API key?

MailerSend takes an API key or an OAuth sign-in. Twilio SendGrid needs an API key.

### Can an agent call MailerSend and Twilio SendGrid without installing anything?

Yes. MailerSend has a hosted endpoint at https://api.mailersend.com/v1 and Twilio SendGrid at https://api.sendgrid.com/v3.


## For agents

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

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