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Alternatives

Postmark alternatives

Four email services a developer leaving Postmark would actually consider, weighed on inbound mail, signed webhooks, agent tooling and what an extra thousand emails costs. Every figure was read from the vendor's own page on 2026-09-16.

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Postmark
Postmark is a transactional email service with six official libraries, an SMTP option and Message Streams, which keep transactional and broadcast mail on separate sending infrastructure.
What this page is
A list of four email services that would take the mail Postmark sends for you today, compared on the same rows and against the same sources. Rasket is one of them, and we build it — so every claim we make about ourselves is linked to a Rasket page, and every claim about anybody else is linked to theirs.

Key takeaways

  • Extra emails, per 1,000 — Rasket: $0.60. Postmark: $1.80.
  • Entry paid plan — Rasket: $20 a month for 50,000 emails. Postmark: $15 a month for 10,000 emails.
  • Free plan — Rasket: 3,000 emails a month, 100 a day, 3 domains. Postmark: 100 emails a month, and it does not expire.
  • Inbound email — Rasket: Yes. Postmark: On the Pro and Platform plans.
  • Official SDKs — Rasket: Node.js and Python. Postmark: Node.js and TypeScript, Python, Ruby, PHP, Java and .NET.

Why developers look for a Postmark alternative

Three reasons that are rows of the table below rather than opinions. Each one is something Postmark publishes about itself.

  • Their documentation states that Postmark does not sign webhooks with HMAC, so a receiver authenticates the sender some other way.
  • Fifty thousand emails is $55 a month on Basic, and extra mail is $1.80 per thousand.
  • Inbound email processing is listed against the Pro and Platform plans, not the entry one.

None of those is a reason on its own. They are reasons if they describe what you are doing: a product past its free tier, a support conversation longer than the history you can read, a campaign you would rather not buy twice.

Four alternatives to Postmark

Rasket is first because we build it, and you should read the table before you take our word for the order.

  1. 1.Rasket

    Yes, and the webhook row is the reason most teams look. Postmark's documentation states that they do not sign webhooks with HMAC; Rasket signs every event and you can replay one from the dashboard. Rasket also includes inbound mail on every plan and charges $0.60 per extra thousand against $1.80. Postmark keeps history longer by default — 45 days against 30 — and has more client languages, so weigh those before moving.

    Best for: Developers who want sending, receiving and broadcasts behind one API key

  2. 2.Mailgun

    Mailgun is an email API from Sinch with six official SDKs, an SMTP relay, rule-based inbound routing and signed webhooks, sold on plans whose log retention grows with the tier. Free plan: 100 emails a day. Extra emails, per 1,000: From $1.80 on Basic.

    Best for: Teams who route inbound mail with rules and want a relay in front of it

  3. 3.MailerSend

    MailerSend is an email API with six official libraries, an SMTP relay, signed webhooks and an MCP server, sold on small plans that start below every other entry price here. Free plan: 500 emails a month, 1 domain, 1 template. Extra emails, per 1,000: $1.30 on Starter and Professional.

    Best for: Small projects that want the cheapest paid plan on this list

  4. 4.Brevo

    Brevo is a marketing platform with a transactional email API attached: an SMTP relay, three official SDKs, secured webhooks, inbound parsing, idempotency keys for batch sends and an MCP server over its developer documentation. Free plan: Not published. Extra emails, per 1,000: Not published.

    Best for: Teams who want marketing, CRM and transactional email from one vendor

The four, row by row

The same rows for all four, with the source of every cell numbered at the foot of the page.

Four alternatives to Postmark, compared row by row
CriterionRasketMailgunMailerSendBrevo
Inbound emailYes Rasket, source 1Receive at your own domain on every plan, delivered as a signed webhook.1 route on Free, 5 on Basic, full routing from Foundation Mailgun, source 13On the Starter and Professional plans MailerSend, source 19Yes Brevo, source 24Inbound parse webhooks, documented in their developer guide.
Transactional and broadcasts on one planYes Rasket, source 2A broadcast travels the same send pipeline as a password reset, on the same plan and the same key.Not published Mailgun, source 13Not published MailerSend, source 19Marketing campaigns and transactional email are both in the API Brevo, source 25
Signed webhooksYes Rasket, source 3Yes Mailgun, source 14A token, a timestamp and an HMAC-SHA256 signature posted with the event.Yes MailerSend, source 20A Signature header holding an HMAC-SHA256 of the body, keyed by a per-webhook signing secret.Yes Brevo, source 26Their secured webhooks guide.
Replay a webhook eventYes Rasket, source 3Send the event again from the dashboard or the API; a replay carries the identical payload under the same event id.Not published Mailgun, source 15Not published MailerSend, source 20Not published Brevo, source 25
Idempotent sendsYes Rasket, source 4An Idempotency-Key is remembered for 24 hours.Not published Mailgun, source 16Not published MailerSend, source 21For batch transactional email Brevo, source 27
Versioned templatesYes Rasket, source 5Published versions with typed variables; every send records the version it used.Not published Mailgun, source 16Not published MailerSend, source 21Not published Brevo, source 25
AutomationsYes Rasket, source 6Not published Mailgun, source 13Not published MailerSend, source 19Workflows, started by events their tracker records Brevo, source 28
MCP serverYes Rasket, source 7An HTTP MCP server with seven toolsets, plus a setup skill.Yes Mailgun, source 17Yes MailerSend, source 22Yes Brevo, source 29
Markdown docs and llms.txtYes Rasket, source 8Markdown at every docs URL, with llms.txt and llms-full.txt.Yes Mailgun, source 16A .md suffix on a documentation URL returns Markdown, and llms.txt maps the set.An llms.txt index MailerSend, source 23The index is published; a .md suffix on a help URL answered 404 on the day.Yes Brevo, source 25A .md suffix on a developer documentation URL returns Markdown, and llms.txt indexes them.
Official SDKsNode.js and Python Rasket, source 9Ruby, PHP, Python, Java, Go and Node.js Mailgun, source 18PHP, Node.js, Go, Python, Ruby and Java MailerSend, source 21Node.js, Python and PHP Brevo, source 30
Free plan3,000 emails a month, 100 a day, 3 domains Rasket, source 10100 emails a day Mailgun, source 13500 emails a month, 1 domain, 1 template MailerSend, source 19Not published Brevo, source 31Their pricing page builds its plan table in the browser; nothing could be read from the page itself on the day.
Entry paid plan$20 a month for 50,000 emails Rasket, source 10$15 a month for 10,000 emails Mailgun, source 13The Basic plan.$7 a month for 5,000 emails MailerSend, source 19The Hobby plan, paying monthly; the page opens on yearly billing, where the same plan is $5.60 a month.Not published Brevo, source 31Same page, same reason.
Extra emails, per 1,000$0.60 Rasket, source 10The rate steps down to $0.25 as the Scale ladder climbs.From $1.80 on Basic Mailgun, source 13From $1.30 on Foundation and from $1.10 on Scale.$1.30 on Starter and Professional MailerSend, source 19The page does not state a rate for the entry Hobby plan.Not published Brevo, source 31Same page, same reason.
Data retention30 days on the self-serve plans Rasket, source 10Custom retention on a Custom plan.1 day of logs on Free and Basic, 5 on Foundation, 30 on Scale Mailgun, source 131 day on Free and Hobby, 7 on Starter, 30 on Professional MailerSend, source 19Not published Brevo, source 31
Dedicated IPAn add-on on Scale Rasket, source 10One included on Scale, extra IPs $59 a month each Mailgun, source 13An add-on above 100,000 emails a week MailerSend, source 19The page does not state its price.Not published Brevo, source 31
SMTP relayNo Rasket, source 11Sending is the REST API, the SDKs and the MCP server. There is no relay to point a mail client at.Yes Mailgun, source 13Yes MailerSend, source 19Yes Brevo, source 32
DKIM key size2048-bit, one key per domain Rasket, source 12Not published Mailgun, source 16Not published MailerSend, source 21Not published Brevo, source 25
Best forDevelopers who want sending, receiving and broadcasts behind one API keyTeams who route inbound mail with rules and want a relay in front of itSmall projects that want the cheapest paid plan on this listTeams who want marketing, CRM and transactional email from one vendor

Moving your domain off Postmark

Add the domain in Rasket and publish the generated DKIM, SPF and DMARC records; verification runs on its own and you can keep sending through Postmark meanwhile. Then swap the call — POST /emails carries the same fields as their email endpoint, and a template alias becomes a Rasket template published as a version. Point your webhook handler at Rasket's signed events, verify the signature rather than the basic-auth credentials you were checking, and replay a delivery from the dashboard to test it.

Nothing about a verified sending domain is exclusive, so both providers can hold it while you move. Send a small share of your mail through the new one first, watch the delivery and bounce events, and cut the rest over once the numbers look like the old ones.

Frequently asked questions

What is the best Postmark alternative for developers?

We build Rasket, so read this as a disclosed preference and not a verdict. Yes, and the webhook row is the reason most teams look. Postmark's documentation states that they do not sign webhooks with HMAC; Rasket signs every event and you can replay one from the dashboard. Rasket also includes inbound mail on every plan and charges $0.60 per extra thousand against $1.80. Postmark keeps history longer by default — 45 days against 30 — and has more client languages, so weigh those before moving.

Is there a free Postmark alternative?

Rasket: 3,000 emails a month, 100 a day, 3 domains. Mailgun: 100 emails a day. MailerSend: 500 emails a month, 1 domain, 1 template. Brevo: Not published. Each figure is from that vendor's own pricing page on 2026-09-16.

Which Postmark alternative includes inbound email?

Rasket: Yes. Mailgun: 1 route on Free, 5 on Basic, full routing from Foundation. MailerSend: On the Starter and Professional plans. Brevo: Yes. Inbound means receiving mail at your own domain, not just sending from it.

Which Postmark alternative works with AI agents?

Rasket: Yes. Mailgun: Yes. MailerSend: Yes. Brevo: Yes. An MCP server is what lets an assistant call the API directly; Markdown docs and llms.txt is the other half, and it reads: Rasket: Yes. Mailgun: Yes. MailerSend: An llms.txt index. Brevo: Yes.

How do I move my domain off Postmark?

Add the domain in Rasket and publish the generated DKIM, SPF and DMARC records; verification runs on its own and you can keep sending through Postmark meanwhile. Then swap the call — POST /emails carries the same fields as their email endpoint, and a template alias becomes a Rasket template published as a version. Point your webhook handler at Rasket's signed events, verify the signature rather than the basic-auth credentials you were checking, and replay a delivery from the dashboard to test it.

Sources

  1. 1. Rasket — http://localhost:3000/features/receiving. Read 2026-09-16.
  2. 2. Rasket — http://localhost:3000/features/broadcasts. Read 2026-09-16.
  3. 3. Rasket — http://localhost:3000/features/webhooks. Read 2026-09-16.
  4. 4. Rasket — http://localhost:3000/docs/idempotency. Read 2026-09-16.
  5. 5. Rasket — http://localhost:3000/features/templates. Read 2026-09-16.
  6. 6. Rasket — http://localhost:3000/features/automations. Read 2026-09-16.
  7. 7. Rasket — http://localhost:3000/features/agents. Read 2026-09-16.
  8. 8. Rasket — http://localhost:3000/llms.txt. Read 2026-09-16.
  9. 9. Rasket — http://localhost:3000/about. Read 2026-09-16.
  10. 10. Rasket — http://localhost:3000/pricing. Read 2026-09-16.
  11. 11. Rasket — http://localhost:3000/features/email-api. Read 2026-09-16.
  12. 12. Rasket — http://localhost:3000/features/domains. Read 2026-09-16.
  13. 13. Mailgun — https://www.mailgun.com/pricing/. Read 2026-09-16.
  14. 14. Mailgun — https://documentation.mailgun.com/docs/mailgun/user-manual/webhooks/securing-webhooks. Read 2026-09-16.
  15. 15. Mailgun — https://documentation.mailgun.com/docs/mailgun/user-manual/webhooks/webhooks. Read 2026-09-16.
  16. 16. Mailgun — https://documentation.mailgun.com/llms.txt. Read 2026-09-16.
  17. 17. Mailgun — https://documentation.mailgun.com/docs/mailgun/mcp. Read 2026-09-16.
  18. 18. Mailgun — https://documentation.mailgun.com/docs/mailgun/sdk/introduction. Read 2026-09-16.
  19. 19. MailerSend — https://www.mailersend.com/pricing. Read 2026-09-16.
  20. 20. MailerSend — https://developers.mailersend.com/api/v1/webhooks.html. Read 2026-09-16.
  21. 21. MailerSend — https://developers.mailersend.com/. Read 2026-09-16.
  22. 22. MailerSend — https://developers.mailersend.com/mcp. Read 2026-09-16.
  23. 23. MailerSend — https://www.mailersend.com/llms.txt. Read 2026-09-16.
  24. 24. Brevo — https://developers.brevo.com/docs/inbound-parse-webhooks. Read 2026-09-16.
  25. 25. Brevo — https://developers.brevo.com/llms.txt. Read 2026-09-16.
  26. 26. Brevo — https://developers.brevo.com/docs/secured-webhooks. Read 2026-09-16.
  27. 27. Brevo — https://developers.brevo.com/docs/heterogenous-versions-batch-emails. Read 2026-09-16.
  28. 28. Brevo — https://developers.brevo.com/guides/track-website-activity. Read 2026-09-16.
  29. 29. Brevo — https://developers.brevo.com/docs/mcp-protocol. Read 2026-09-16.
  30. 30. Brevo — https://developers.brevo.com/docs/api-clients. Read 2026-09-16.
  31. 31. Brevo — https://www.brevo.com/pricing/. Read 2026-09-16.
  32. 32. Brevo — https://developers.brevo.com/docs/smtp-integration. Read 2026-09-16.

Last checked 2026-09-16. Prices and plan contents change. Every figure above was read from the linked page on the date beside it; if one has moved since, the page it came from is the one to trust.

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