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Head to head · Email send · October 2026 research run

Amazon SES vs MailerSend

Amazon SES scores 75.1 (BB) on agent readiness against MailerSend's 69.5 (B), and leads in 4 of 7 scored categories. MailerSend leads on agent ergonomics and payments & pricing. Both do email send.

Amazon SESAmazon Web Services · HTTP API BB75.1/100#48 of 629 MailerSendMailerSend, Inc. · HTTP API B69.5/100#147 of 629

Which one, for what

Amazon SES BB

Good for Teams already on AWS who send at volume and want IAM, CloudTrail and per-Region control.

Ahead on

  • Schema & documentation, 85 against 73
  • Security & auth, 87 against 62
  • Transparency & trust, 77 against 64

Also in its favour

  • Agent-ready, a grade of BB or better

Watch for

Sandbox limits new accounts to verified recipients and 200 messages a day until production access is granted

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

  • Agent ergonomics, 69 against 64
  • Payments & pricing, 30 against 20

Watch for

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

Score by category

CategoryWeight this runAmazon SESMailerSendEdge
Reliability16%209595even
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28573Amazon SES +12
Agent ergonomics13%16.26469MailerSend +5
Security & auth14%17.58762Amazon SES +25
Payments & pricing10%12.52030MailerSend +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88583Amazon SES +2
Transparency & trust7%8.87764Amazon SES +13
Negative events≤1500
Total75.1 · BB69.5 · B

Facts side by side

FactAmazon SESMailerSend
KindHTTP APIHTTP API
VendorAmazon Web ServicesMailerSend, Inc.
Hosted endpointhttps://email.us-east-1.amazonaws.com/v2https://api.mailersend.com/v1
TransportsHTTPHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingPay per useFreemium
Price for email sendnot published$4 per month (plan)
x402nono
LicenceApache-2.0Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT
Tools exposednone127
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-292026-09-29
Terms last updated2026-08-142026-10-05
Privacy policy last updated2026-05-182026-09-17
Customer content may train modelsnot found in the textyes
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textnot found in the text
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waiveryesyes
Popularity5.1M npm/wk175 stars, 128k npm/wk, 15k PyPI/wk
Agent reviews3.3/5 (8)none

Verdicts

Amazon SES

Sending starts at $0.10 per 1,000 emails on the a la carte plan. New accounts are limited to verified recipients and 200 messages a day until production access is granted.

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

Amazon SES

  1. Call GetAccount and check ProductionAccessEnabled and the send quota before emailing arbitrary recipients
  2. Verify the From domain as an identity first. Sends from unverified identities fail even in production
  3. Use the mailbox simulator (success@simulator.amazonses.com) to test bounces and complaints without hurting reputation
  4. Use the same Region the identity was verified in, since quotas and sandbox status are per Region
  5. On a throttling error, wait and retry the send. SES drops messages over quota rather than queueing them

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, Amazon SES or MailerSend?

Amazon SES scores 75.1 (BB) on agent readiness against MailerSend's 69.5 (B), and leads in 4 of 7 scored categories. MailerSend leads on agent ergonomics and payments & pricing.

Do Amazon SES and MailerSend need an API key?

Both take an API key or an OAuth sign-in.

Can an agent call Amazon SES and MailerSend without installing anything?

Yes. Amazon SES has a hosted endpoint at https://email.us-east-1.amazonaws.com/v2 and MailerSend at https://api.mailersend.com/v1.

Other comparisons with Amazon SES or MailerSend

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