Mailgun vs Postmark
Mailgun and Postmark are both popular choices in the transactional email service space. Both start at $15/mo. Both offer free plans to get started.
Quick Verdict
Mailgun wins on integrations.
Postmark wins on deliverability, rating.
Best for most users: Postmark (saas applications).
Mailgun
Developer-focused transactional email API by Sinch
Mailgun is a Sinch-owned transactional email API platform founded in 2010, designed for developers who need reliable, high-volume email delivery via REST API or SMTP. It offers email validation, inbox placement testing, and send-time optimization, making it a solid choice for SaaS companies and engineering teams building custom email workflows.
Postmark
Transactional email with exceptional deliverability, now by ActiveCampaign
Postmark, originally built by Wildbit and acquired by ActiveCampaign in 2022, is a transactional email service laser-focused on deliverability and speed. It consistently achieves near-99% inbox placement rates and processes emails in sub-second times, making it the top choice for developers who refuse to compromise on email reaching the inbox.
Feature Comparison
| Feature | Mailgun | Postmark |
|---|---|---|
| Rating | 4.2/5 | 4.6/5 |
| Starting Price | $15/mo | $15/mo |
| Free Plan | 100 emails/day (~3,000/month), 1 domain, 1-day logs | 100 emails/month, never expires, test integration and side projects |
| Founded | 2010 | 2009 |
| Email Templates | 25 | 20 |
| Integrations | 40 | 30 |
| Deliverability Rate | 97% | 98.7% |
| Marketing Automation | ✕ | ✕ |
| A/B Testing | ✕ | ✕ |
| Landing Pages | ✕ | ✕ |
| Segmentation | ✕ | ✕ |
| Drag & Drop Editor | ✕ | ✕ |
| SMS Marketing | ✕ | ✕ |
| Ecommerce Features | ✕ | ✕ |
| API Access | ✓ | ✓ |
| Multi-Language | ✕ | ✕ |
| Web Push Notifications | ✕ | ✕ |
| Live Chat | ✕ | ✕ |
| Advanced Analytics | ✓ | ✓ |
Mailgun: Pros & Cons
Pros
- +Powerful RESTful API with well-structured SDKs for Python, Ruby, Node.js and more, making integration painless for developers
- +Real-time dashboards for delivery, bounce, spam complaints, and click rates provide clear campaign health visibility
- +Handles very high email volumes reliably with strong deliverability and fast sending speeds
- +Built-in email validation and inbox placement testing tools (Mailgun Optimize) for deliverability optimization
- +Flexible routing rules, webhooks, and event tracking simplify debugging and monitoring email performance
Cons
- −Pricing escalates quickly at higher volumes and premium features like dedicated IPs ($59/mo) and validations cost extra
- −No built-in drag-and-drop email editor or marketing automation features — purely developer-focused
- −Setup requires technical knowledge; non-developers will struggle with DNS configuration and API integration
- −UI dashboard feels outdated in certain sections compared to modern competitors like Resend
- −Lower-tier plans use shared IP addresses which can impact deliverability if other senders have poor practices
Postmark: Pros & Cons
Pros
- +Industry-leading deliverability rates — 98.7% inbox placement confirmed in third-party tests by Hackceleration (2026)
- +Extremely fast email delivery with sub-second processing times for transactional messages
- +Clean, intuitive dashboard with detailed delivery analytics including bounce tracking, spam complaints, and open rates
- +Pre-built responsive HTML templates for common transactional emails (welcome, password reset, receipts, invoices)
- +Simple, volume-based pricing with no hidden fees — free tier never expires and is great for testing
Cons
- −Very limited free tier at only 100 emails/month compared to competitors offering thousands
- −No marketing email features — strictly transactional and broadcast; no automation, sequences, or segmentation
- −Some users report customer service quality declined after the ActiveCampaign acquisition in 2022
- −No built-in drag-and-drop email editor; templates require HTML knowledge to customize
- −Overage rates ($1.20-$1.80 per 1,000) can add up quickly for unpredictable sending volumes
The Verdict
Postmark edges ahead with a 4.6/5 rating compared to Mailgun's 4.2/5. The gap comes mainly from deliverability (5 vs 4.5) and feature depth (4.2 vs 3.8). On deliverability, Postmark reports 98.7% compared to 97% for Mailgun — a meaningful difference if inbox placement is critical for your campaigns.
| Criterion | Weight | Mailgun | Postmark |
|---|---|---|---|
| Starting Price | 30% | $15/mo | $15/mo |
| Deliverability | 25% | 97% | 98.7% |
| Rating | 25% | 4.2/5 | 4.6/5 |
| Integrations | 10% | 40 | 30 |
| Free Tier | 10% | Yes | Yes |
Weights determine how much each criterion counts toward the final score. See full methodology
Choose Mailgun if…
- + You're a developers
- + You're a saas companies
- + Powerful RESTful API with well-structured SDKs for Python, Ruby, Node.js and more, making integration painless for developers
Choose Postmark if…
- + You're a saas applications
- + You're a transactional email senders
- + Industry-leading deliverability rates — 98.7% inbox placement confirmed in third-party tests by Hackceleration (2026)