In-depth two-product comparison
Postmark vs Mailgun
In-depth comparison of Postmark and Mailgun for B2B SaaS companies. We analyze deliverability, speed, pricing, API quality, and features.
Last updated: 2026-03-15. Verify current features, pricing, limits, and integrations on official vendor pages.
Short answer
Postmark wins on deliverability, delivery speed, and inbox placement through strict sender policies. Mailgun wins on feature breadth with email validation, flexible inbound routing, and lower pricing at scale. Postmark is best when transactional email quality is your top priority. Mailgun is better for teams needing validation and inbound features. Sequenzy is the strongest choice for SaaS lifecycle email with native billing integration.
Postmark
The gold standard for fast, reliable transactional email
Mailgun
The developer email platform with SMTP, inbound, and validation
Quick comparison
| Decision area | Postmark | Mailgun | What to verify |
|---|---|---|---|
| Best For | Fastest, most reliable transactional delivery | Teams needing SMTP, inbound, and validation | Test this with representative data and the next realistic usage tier. |
| Starting Price | $15/mo for 10,000 emails | $35/mo for 50,000 emails | Test this with representative data and the next realistic usage tier. |
| Delivery Speed | Industry-leading, publicly tracked | Decent, some variance | Test this with representative data and the next realistic usage tier. |
| Inbox Placement | ~98-99% (strict sender policies) | ~92-96% (shared IPs vary) | Test this with representative data and the next realistic usage tier. |
| Email Validation | Not available | Mailgun Optimize (real-time + bulk) | Test this with representative data and the next realistic usage tier. |
| Inbound Email | Full inbound processing | Flexible inbound routing | Test this with representative data and the next realistic usage tier. |
| Message Streams | Separate transactional/broadcast | Single pipeline with tags | Test this with representative data and the next realistic usage tier. |
| SMTP Support | Full SMTP | Full SMTP with routing rules | Test this with representative data and the next realistic usage tier. |
| Payment Integration | None | None | Test this with representative data and the next realistic usage tier. |
| Dedicated IP | On higher plans | On Scale ($90/mo) | Test this with representative data and the next realistic usage tier. |
| Status Transparency | Public real-time delivery speed metrics | Standard status page | Test this with representative data and the next realistic usage tier. |
Feature comparison
| Feature | Postmark | Mailgun |
|---|---|---|
| Delivery speed | 10/10
Industry-leading, publicly tracked | 7/10
Decent speed with some variance |
| Inbox placement | 10/10
Highest in industry, strict sender policies | 6/10
Variable shared IP quality |
| Template system | 7/10
Mustache templates with layout support | 5/10
Handlebars via API, no visual editor |
| Bounce handling | 9/10
Best-in-class with reactivation tools | 7/10
Standard bounce processing |
| Message streams | 9/10
Separate transactional/broadcast for reputation | 5/10
Single pipeline with tag-based categorization |
| Email validation | 0/10
Not available | 9/10
Mailgun Optimize real-time and bulk validation |
| Inbound processing | 9/10
Full inbound with JSON webhook delivery | 8/10
Flexible routing rules |
| Email routing | 6/10
Standard stream-based | 9/10
Flexible routing rules for complex workflows |
| Spam testing | 8/10
SpamAssassin pre-send analysis | 6/10
Inbox placement testing via Optimize |
| Status transparency | 10/10
Public real-time delivery speed dashboard | 5/10
Standard status page |
| API design | 8/10
Clean, well-organized | 6/10
Functional but dated |
| Documentation | 9/10
Clear docs with developer blog | 6/10
Adequate but hard to navigate |
| SDK quality | 8/10
Official SDKs in 6 languages | 6/10
Official SDKs, some dated |
| Webhooks | 9/10
Reliable with retry and batch delivery | 7/10
Event webhooks, configurable retry |
| Sandbox testing | 8/10
Dedicated test server | 6/10
Test mode available |
| Dashboard | 8/10
Clean activity feed with search | 7/10
Analytics dashboard with charts |
| Bounce analytics | 9/10
Bounce trends with reactivation | 7/10
Bounce handling |
| Open/click tracking | 7/10
Optional (off by default for privacy) | 8/10
Enabled by default |
| Log retention | 8/10
45 days activity retention | 5/10
5-30 days depending on plan |
| Revenue attribution | 0/10
Not available | 0/10
Not available |
| Billing integration | 0/10
Not available | 0/10
Not available |
| Lifecycle sequences | 0/10
No automation | 0/10
No automation |
| Dunning emails | 0/10
Not available | 0/10
Not available |
| Trial conversion | 0/10
Not available | 0/10
Not available |
| Revenue attribution | 0/10
Not available | 0/10
Not available |
Pricing and operating cost
Postmark
Free trial: 100 test emails, then $15/mo
No marketing automation Per-email pricing expensive at very high volume Dedicated IP on higher plans only Acquired by ActiveCampaign (direction concerns)
Mailgun
Free trial, then $35/mo
Email validation is a paid add-on 5 days log retention on starter Dedicated IP extra on lower plans IP pool fees
| Tier or usage case | Postmark | Mailgun |
|---|---|---|
| Starter | $15/mo 10,000 emails, all features included | $35/mo 50,000 emails, 5 days log retention |
| Growth | $50/mo 50,000 emails, priority support | $90/mo 100,000 emails, dedicated IP, 15 days logs |
| Scale | $175/mo 300,000 emails, dedicated IP available | $350+/mo 500K+ emails, 30 days logs, SLA |
Pros and cons
Postmark
Pros
- Industry-leading delivery speed and inbox placement
- Strict sender policies protect reputation
- Message stream separation
- Full inbound processing
- Public real-time speed dashboard
- Excellent bounce handling with reactivation
- Clean API with good docs
- Privacy-first tracking approach
Cons
- No marketing automation
- No email validation
- Per-email pricing expensive at very high volume
- No visual campaign builder
- Acquired by ActiveCampaign
- No SaaS billing integration
- Fewer SDK languages than Mailgun
- Limited broadcast capabilities
Mailgun
Pros
- Built-in email validation (Mailgun Optimize)
- Flexible inbound routing
- SMTP with routing rules
- Action Mailer support
- Tag-based analytics
- Recipient variable batch sending
- Go SDK available
- More emails per dollar than Postmark
Cons
- Shared IP reputation inconsistent
- No marketing automation
- Short log retention on lower plans
- Documentation hard to navigate
- SDKs feel dated
- Multiple ownership changes
- No SaaS lifecycle features
- No message stream separation
Who should choose what?
Email speed and reliability are non-negotiable.
Recommendation: Postmark
High-volume signups need verification.
Recommendation: Mailgun
Need email infrastructure fast.
Recommendation: Mailgun
Billing-aware lifecycle email needed.
Recommendation: Mailgun
Ruby on Rails with Action Mailer.
Recommendation: Postmark
Need transactional and lifecycle on a budget.
Recommendation: Mailgun
Final verdict
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FAQ
Is Postmark faster than Mailgun?
Yes. Postmark consistently delivers faster than Mailgun and publicly tracks performance. Mailgun is reliable but not as fast.
Does Mailgun have better email validation?
Mailgun is the only option with built-in validation. Postmark does not offer email address validation, only SpamAssassin content analysis.
Which has better inbox placement?
Postmark has significantly better inbox placement due to strict sender policies. Mailgun shared IPs can be inconsistent.
Can both handle inbound email?
Yes. Postmark has clean JSON webhook delivery. Mailgun has more flexible routing rules. Both are strong for inbound.
Related reading: B2B email marketing guide , alternatives hub , and B2B SaaS tool stack .