Head to head
Mailgun vs Postmark
As a transactional email API, Postmark rates higher on the APIbenchmarks Index, 84.2 to 82.1, a 2.1-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | Mailgun | Postmark |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 82.1 | 84.2 |
Specifications
| Mailgun | Postmark | |
|---|---|---|
| Best for | Developer email infrastructure at scale | Fast, high-deliverability transactional mail |
| Free tier | 100 emails/day (forever) | 100 emails/mo (never expires) |
| Pricing | Per monthly email volume | Per monthly email volume |
| Official SDKs | 9 languages | 12 languages |
Is Mailgun better than Postmark?
On the APIbenchmarks Index, Postmark rates higher (84.2 vs 82.1). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
Postmark leads by 2.1 points (84.2 vs 82.1) and wins 2 of 4 criteria; Mailgun wins 2.
Winner by criterion
| Criterion | Winner | ||
|---|---|---|---|
| Documentation & DX | 80 | 88 | |
| Reliability | 86 | 85 | |
| Ecosystem & SDKs | 84 | 78 | |
| Accessibility | 78 | 85 |
Choose Mailgun if… / choose Postmark if…
- →reliability matters most to you (86 vs 85)
- →ecosystem & sdks matters most to you (84 vs 78)
- →your use case matches its focus: developer email infrastructure at scale
- →documentation & dx matters most to you (88 vs 80)
- →accessibility matters most to you (85 vs 78)
- →you need broad SDK coverage (12 official SDKs vs 9)
- →your use case matches its focus: fast, high-deliverability transactional mail
Pricing side by side
- Model
- Per monthly email volume
- Free tier
- 100 emails/day (forever)
- Free$0/mo
- Basicfrom $15/mo
- Foundation$35/mo
- Scale$90/mo
- EnterpriseCustom (contact sales)
- Model
- Per monthly email volume
- Free tier
- 100 emails/mo (never expires)
- Developer (Free)$0/mo
- Basic$15/mo
- Pro (Most Popular)$16.50/mo
- Platform$18/mo
- Dedicated IP add-onfrom $50/mo per IP
Vendor-published pricing, verified 2026-06-27 (Mailgun) and 2026-06-27 (Postmark).
SDK and language coverage
Both · 5
PythonPHPJavaNode.jsGo
Only Mailgun · 4
RubyC#/.NETREST APISMTP relay
Only Postmark · 7
Ruby / Rails.NETElixir (community)Django (community)ColdFusion (community)Clojure (community)Haskell (community)
Strengths and weaknesses
- +Clean, well-documented REST API plus SMTP relay; reviewers report integration in minutes
- +Seven official, actively maintained SDKs (Python, Ruby, PHP, Java, C#, Node.js, Go)
- +Contractual 99.99% uptime SLA on core API/SMTP/outbound delivery for all plan tiers
- –Pricing escalates steeply with volume; reviewers say it has gotten 'pricier and pricier'
- –Legacy pay-as-you-go Flex plan doubled to $2.00/1K in Dec 2025 and is closed to new users
- –Recurring abrupt account suspensions, sometimes right after signup or mid-integration, with no clear reason
- +Best-in-class, publicly transparent deliverability: live Time-to-Inbox and inbox-placement data per ISP, ~99% inbox placement in independent tests
- +Very fast delivery: published figures show 50% of emails in inbox in 0.57s, 95% within 1.95s
- +Message Streams cleanly separate transactional from broadcast traffic to protect sender reputation
- –Expensive at scale, ~$600-900/mo for 500k emails vs ~$50 on Amazon SES; economics favor SES/Mailgun beyond ~200k/month
- –No annual plans, and no payment via invoice or PayPal
- –Narrower than marketing-first platforms, limited campaign/marketing-automation tooling
Mailgun vs Postmark: questions
- Which has better documentation, Mailgun or Postmark?
- Postmark scores higher on documentation and developer experience: 88 vs 80 out of 100.
- Which is more reliable, Mailgun or Postmark?
- Mailgun scores higher on reliability: 86 vs 85 out of 100.
- Do Mailgun and Postmark have a free tier?
- Mailgun: yes (100 emails/day (forever)). Postmark: yes (100 emails/mo (never expires)).
- How are Mailgun and Postmark priced?
- Mailgun: Per monthly email volume. Postmark: Per monthly email volume.
- Which has more official SDKs?
- Postmark lists 12 official SDKs, Mailgun lists 9.