Mailgun vs Postmark vs Resend
Mailgun vs Postmark vs Resend compared for developers: what each is best at, deliverability reputation, developer experience, and pricing model — plus how to choose.
Overview
Mailgun, Postmark, and Resend are three popular developer email APIs that lead on different things, so the "best" depends on what you weight. Postmark is known for transactional speed and deliverability; Resend for modern developer experience; Mailgun for flexibility and scale, including EU regions and validation tooling. Here's an honest head-to-head and how to choose between them.
What each is best at
Postmark built its reputation on fast, reliable transactional delivery and a deliberate separation of transactional and broadcast streams — a favourite when getting password resets to the inbox quickly matters most. Resend is the newest and leads on developer experience: clean SDKs, React Email, and a modern dashboard, popular with startups. Mailgun is the most established and flexible — strong API, email validation, EU data regions, and scale — though some find it heavier and its support tiering frustrating.
All three deliver well when configured right; the differences are emphasis, DX, and ecosystem rather than whether the mail arrives.
- Postmark — transactional speed + deliverability reputation
- Resend — best modern DX (SDKs, React Email)
- Mailgun — flexible, scalable, EU regions, validation
- All deliver well configured right — emphasis differs
| Postmark | Resend | Mailgun | |
|---|---|---|---|
| Best at | Transactional delivery | Developer experience | Flexibility/scale |
| Vibe | Reliable, focused | Modern, startup | Established, flexible |
| Pricing model | Per-email tiers | Freemium + tiers | Volume tiers |
How to choose
Pick Postmark if transactional deliverability is the priority and you like its focused, opinionated approach. Pick Resend if developer experience and a modern stack matter most and you're early. Pick Mailgun if you need flexibility, EU data residency, validation tooling, or are scaling large volumes. Trial two on your real traffic — deliverability in your specific region is the thing demos hide.
All three are hosted APIs, so none let you own delivery — if that's a goal, look at self-hosted useSend on SES instead (see Resend alternatives). And whichever you pick, it's the sending layer; Mailbase adds the workflow layer (reply inbox, campaigns, analytics) on top.
- Postmark: transactional deliverability first
- Resend: DX and a modern stack
- Mailgun: flexibility, EU regions, validation, scale
- Want to own delivery? Self-host useSend on SES instead
Common Mistakes
- Sending product-critical mail and marketing from the same domain/reputation.
- Skipping idempotency, so retries create duplicate sends.
- Ignoring bounce and complaint webhooks until suppression breaks.
- Treating an email API as “fire and forget” with no event logging.
Sources & Further Reading
Official docs for current setup details, pricing, and API behavior — verify specifics there, since they change.
Related guides
More on mailgun vs postmark vs resend and the surrounding transactional email workflow:
FAQ
Mailgun vs Postmark vs Resend — which is best?
Postmark for transactional speed and deliverability, Resend for modern developer experience, Mailgun for flexibility, scale, and EU data regions. All deliver well when configured right, so choose on emphasis, DX, and pricing at your volume — and trial two on your real traffic before committing.
Which has the best deliverability?
Postmark has the strongest reputation specifically for transactional deliverability and keeps transactional and broadcast streams separate. That said, all three deliver well when you authenticate your domain and maintain list hygiene — provider choice matters less than your own SPF/DKIM/DMARC and reputation.
Which is cheapest?
It depends on volume and message mix; pricing models differ (per-email tiers vs freemium vs volume tiers) and change often, so compare on your actual numbers. If lowest cost at scale is the goal, self-hosting useSend on Amazon SES typically beats all three hosted APIs.
Is Resend better than Mailgun and Postmark?
Resend leads on modern developer experience (SDKs, React Email, dashboard), which makes it appealing for new projects, but it's newer than Mailgun and Postmark. For pure transactional deliverability Postmark is the safer reputation; for flexibility and scale, Mailgun. "Better" depends on what you weight.