Compare

Mailgun vs Sendgrid

Mailgun scores higher on the AgentReady, 58/100 against 53/100. They differ on 13 of the 41 signals. Which ones decides whether an agent can adopt them without a person watching.

What each one is

Mailgun. Transactional Email Delivery Service & API for Developers.

Sendgrid. Email delivery platform providing transactional and marketing email solutions, now part of Twilio.

Where Mailgun is ahead

Mailgun passes clear canonical domain and mcp discoverable, and Sendgrid does not. That is discover, whether an agent can find the product at all without being told it exists.

It also holds understand: pricing understandable. Sendgrid misses it.

And on adopt, free trial or free allowance and mcp integration available. Sendgrid misses those.

Finally, on operate, observable execution and agent compatibility verified. Sendgrid misses those.

Where Sendgrid is ahead

Sendgrid passes public docs discoverable, llms.txt published and llms-full.txt / full agent docs, and Mailgun does not. That is discover, whether an agent can find the product at all without being told it exists.

It also holds understand: structured api reference. Mailgun misses it.

And on adopt, no mandatory sales call and cli available. Mailgun misses those.

What neither does

Both fail openapi / spec quality, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented, programmatic credential creation, structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable. If your agent needs any of those, you will be building it yourself either way.

Score, pillar by pillar

The AgentReady splits into four pillars, scored separately, because a product can be easy to find and still impossible to adopt.

Discover. Sendgrid leads 80 to 73. Mailgun misses public docs discoverable, llms.txt published, llms-full.txt / full agent docs; Sendgrid misses clear canonical domain, mcp discoverable.

Understand. Sendgrid leads 38 to 31. Mailgun misses structured api reference, openapi / spec quality, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented; Sendgrid misses openapi / spec quality, pricing understandable, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented.

Adopt. Mailgun leads 75 to 70. Mailgun misses no mandatory sales call, programmatic credential creation, cli available; Sendgrid misses programmatic credential creation, free trial or free allowance, mcp integration available.

Operate is whether an agent can run against it in production and recover when a call fails. Mailgun leads 53 to 24. Mailgun misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable; Sendgrid misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, observable execution, agent compatibility verified.

Pricing

Mailgun does not publish a machine-readable starting price and has a free tier. Sendgrid does not publish one.

Signal by signal

Which to pick

Mailgun clears more of the signals an agent needs, so it is the safer default for unattended use. Full profiles: Mailgun and Sendgrid. Alternatives to each: Mailgun, Sendgrid.

An agent can fetch this as data: POST /v1/compare {"slugs": ["mailgun", "sendgrid"]}