# Mailgun vs Postmark — Transactional Email

As of 2 Nov 2026, the panel rates [Mailgun](https://whats-best.ai/software/transactional-email/mailgun) 2/5 and [Postmark](https://whats-best.ai/software/transactional-email/postmark) 3/5 in Transactional Email. Weighted by what each judge cares about, 2 of the 6 judges pick Mailgun and 4 pick Postmark. Postmark scores higher on 7 of 7 criteria (Sending API, SMTP & developer experience, Deliverability & sender reputation, Reliability, accounts & support, plus 4 more). Provenance — Mailgun: Rest of world; Postmark: Rest of world. Ratings are the AI panel’s opinion, formed from public evidence: [how scores are made](https://whats-best.ai/methodology#ordering).

- Canonical page: https://whats-best.ai/compare/mailgun-vs-postmark
- Mailgun: https://whats-best.ai/software/transactional-email/mailgun ([md](https://whats-best.ai/software/transactional-email/mailgun.md))
- Postmark: https://whats-best.ai/software/transactional-email/postmark ([md](https://whats-best.ai/software/transactional-email/postmark.md))
- Category: [Transactional Email](https://whats-best.ai/software/transactional-email.md)
- Data as of: 2026-11-06

**AI-generated.** Both products were evaluated from public evidence by the same panel of AI judges under the same rubric; without that, no comparison is published. Not a hands-on test; no score can be bought, on either side. How scores are made: https://whats-best.ai/methodology

## The short answer

Postmark's widest leads are the sending API (7.0 to 4.0, six judges lean Postmark) and deliverability (7.5 to 4.5, four lean Postmark, two tie); its means also lead on observability, reliability and accounts, sovereignty and pricing transparency. Mailgun draws more judge leans on data and security, sovereignty and pricing transparency — three to two with one tie on each — even where Postmark's means run higher. Weighted totals split four to two: the developer (6.8 to 6.4), agency lead (6.4 to 6.2), data protection officer (5.8 to 0) and skeptic (6.2 to 0) carry Postmark; the platform engineer (6.5 to 6.4) and ecommerce operator (6.6 to 6.2) carry Mailgun. On sovereignty, Mailgun's pages show a published data processing agreement with standard contractual clauses under Swedish law and a selectable EU region, beside Texas-law contracting; Postmark's show Illinois law and United States storage, with no EU hosting region found on the captured pages.

**Choose Mailgun if:**
- Your team follows the bench lean on data and security, where three judges lean Mailgun, two lean Postmark and one ties.
- You contract under EU terms: Mailgun's captured pages publish a data processing agreement with standard contractual clauses under Swedish law and an EU region the customer must select, and sovereignty leans Mailgun three to two.
- You need a written uptime commitment: Mailgun's pages carry a 99.99% monthly uptime guarantee, while we found no SLA information on Postmark's captured pages.
- Your reviewers match the platform engineer or ecommerce operator, whose weighted totals read 6.5 to 6.4 and 6.6 to 6.2 for Mailgun.
- You send low volumes first: Mailgun's pages list a free tier at 100 emails/day.

**Choose Postmark if:**
- You build against the sending API first: Postmark's mean is 7.0 to Mailgun's 4.0, with six judges leaning Postmark.
- Deliverability decides the purchase: Postmark's mean is 7.5 to 4.5 (four judges lean Postmark, two tie), resting on manual vetting of new senders, free custom Return-Path and DKIM, and separate infrastructure for transactional and broadcast traffic.
- You compare starting prices across pages: Mailgun's captured pages give different figures for the starting price — $15/month for 10,000 emails versus Foundation at $35/mo — while Postmark's pricing transparency mean is 7.0 to 5.2.
- Your operations lean on webhooks: the reliability and accounts mean is 6.2 to 4.0 (three judges lean Postmark, three tie), with strong webhooks and redundancy cited in the verdict.
- Your operations run in the United States: Postmark's captured pages state personal information is stored in AWS and Deft data centres in the United States.

## Overall

| | Mailgun | Postmark |
|---|---|---|
| Panel rating | 2/5 | 3/5 |
| Provenance | Rest of world | Rest of world |
| Sovereignty | not determined | not determined |

## The bench's picks

| Judge | Mailgun | Postmark | Pick |
|---|---|---|---|
| The SaaS Developer | 3/5 | 3.5/5 | Postmark |
| The Platform Engineer | 3.5/5 | 3/5 | Mailgun |
| The Shop Operator | 3.5/5 | 3/5 | Mailgun |
| The Data Protection Officer | 0/5 | 3/5 | Postmark |
| The Agency Lead | 3/5 | 3/5 | Postmark |
| The Skeptic | 0/5 | 3/5 | Postmark |

## Criterion by criterion

Bench average per criterion, out of 5; the lean counts which product each judge scored higher.

| Criterion | Mailgun | Postmark | The bench leans |
|---|---|---|---|
| Sending API, SMTP & developer experience | 2/5 | 3.5/5 | Postmark, 6 of 6 judges |
| Deliverability & sender reputation | 2.5/5 | 4/5 | Postmark, 4 of 6 judges |
| Message logs, events & webhooks | 2.5/5 | 3.5/5 | Postmark, 2 of 6 judges |
| Message data, retention & security | 2.5/5 | 3/5 | Mailgun, 3 of 6 judges |
| Reliability, accounts & support | 2/5 | 3/5 | Postmark, 3 of 6 judges |
| European sovereignty | 1.5/5 | 2/5 | Mailgun, 3 of 6 judges |
| Pricing transparency | 2.5/5 | 3.5/5 | Mailgun, 3 of 6 judges |

## Sovereignty, side by side

| Dimension | Mailgun | Postmark |
|---|---|---|
| Legal entity | Not determined | Not determined |
| Hosting location | Not determined | Not determined |
| Hosting options | Not determined | Not determined |
| Open source | Not determined | Not determined |
| Data processing agreement | Not determined | Not determined |
| Transfer impact assessment | Not determined | Not determined |

## Facts, side by side

Only facts both products carry under the same definition; each is the vendor's own dated statement ([S*n*] → Sources).

| Fact | Mailgun | Postmark |
|---|---|---|
| Compliance · Dpf certification | Mailgun Technologies, Inc. · yes · yes [S1] | yes · yes · yes [S2] |
| Compliance · GDPR | yes [S3] | yes [S4] |
| Compliance · GDPR page | yes · yes [S5] | yes [S6] |
| Compliance · Security measures | yes · yes · yes [S1] | yes [S2] |
| Data · Return deletion | customer responsible for retrieving copy prior to termination · yes · yes · yes [S7] | yes [S8] |
| Integrations · Webhooks | Webhooks push real-time email event data to applications [S9] | Delivery · Bounce · Spam complaint · Open tracking · Click · Subscription change · Inbound · yes [S10] |
| Legal · Copyright | 2026 · Mailgun [S11] | ActiveCampaign, LLC [S12] |
| Legal · DPA available | yes [S3] | yes [S6] |
| Legal · Entity | Mailgun · Mailgun Optimize · Mailjet · Email on Acid · Sinch AB (publ) or its subsidiaries [S1] | AC PM, LLC · Postmark Terms of Service [S13] |
| Legal · Liability cap | fees paid for affected services in preceding 12 months [S14] | fees paid in the 3 months preceding the claim [S13] |
| Pricing · Free | 100 emails/day · 0 [S15] | 0 · 100 · no [S16] |
| Product · Analytics | Real-time opens, clicks, bounces analytics [S17] | yes [S18] |
| Product · Breach notification | written, as soon as reasonably practicable, in accordance with applicable law · yes [S7] | without undue delay · yes [S8] |
| Product · Status page | Unexpected service interruptions are notified via a status page [S19] | yes [S16] |
| Product · Templates | Dynamic templates [S17] | yes · yes [S16] |
| Product · Trial | 30 [S15] | no [S16] |
| Product · User roles | 5 [S15] | yes [S16] |
| Product · Webhooks | yes [S20] | yes · yes [S16] |

## Sources

- [S1] Privacy policy: https://www.mailgun.com/legal/privacy-policy/ (checked 2026-11-01)
- [S2] Privacy policy: https://www.activecampaign.com/legal/privacy-policy (checked 2026-11-01)
- [S3] Message data, retention & security — found from sitemap: https://www.mailgun.com/security/ (checked 2026-11-01)
- [S4] Security / trust page: https://postmarkapp.com/security (checked 2026-11-01)
- [S5] Vendor homepage: https://www.mailgun.com/ (checked 2026-11-01)
- [S6] Security / trust page (EU data protection): https://postmarkapp.com/eu-privacy (checked 2026-11-01)
- [S7] Message data, retention & security — found from sitemap: https://www.mailgun.com/security-privacy/ (checked 2026-11-01)
- [S8] Data processing agreement (dpa): https://postmarkapp.com/dpa (checked 2026-11-01)
- [S9] Reliability, accounts & support — found from sitemap: https://www.mailgun.com/integrations/ (checked 2026-11-01)
- [S10] API documentation: https://postmarkapp.com/developer (checked 2026-11-01)
- [S11] Deliverability & sender reputation — found from sitemap: https://www.mailgun.com/solutions/email-blocklist-monitoring-service/ (checked 2026-11-01)
- [S12] Message data, retention & security — found from sitemap: https://postmarkapp.com/support/article/what-tls-does-postmark-support-and-use (checked 2026-11-01)
- [S13] Terms of service: https://postmarkapp.com/terms-of-service (checked 2026-11-01)
- [S14] Terms of service: https://www.mailgun.com/legal/terms/ (checked 2026-11-01)
- [S15] Pricing page: https://www.mailgun.com/pricing/ (checked 2026-11-01)
- [S16] Pricing page: https://postmarkapp.com/pricing (checked 2026-11-01)
- [S17] Sending API, SMTP & developer experience — found from sitemap: https://www.mailgun.com/integrations/mailgun-api/ (checked 2026-11-01)
- [S18] Vendor homepage: https://postmarkapp.com/ (checked 2026-11-01)
- [S19] Reliability, accounts & support — found from sitemap: https://www.mailgun.com/legal/sla/ (checked 2026-11-01)
- [S20] Features page (email API): https://www.mailgun.com/features/email-api/ (checked 2026-11-01)

## Questions

### Which is better, Mailgun or Postmark?

As of 2 Nov 2026, the panel rates Postmark higher: 3/5 against 2/5. Weighted by what each judge cares about, 2 of the 6 judges pick Mailgun and 4 pick Postmark. Which one fits depends on the criteria that matter to you; the table on this page shows both side by side, and each judge’s reading has its own page. Both were scored by the same AI bench under the same rubric, from public evidence only, [as the methodology describes](https://whats-best.ai/methodology).

### Is Mailgun or Postmark European?

Mailgun is not European by provenance (Rest of world). Postmark is not European by provenance (Rest of world). Provenance is read from each company’s own legal pages: who builds it and who owns it.

### Where do Mailgun and Postmark store customer data?

Per the vendors’ own pages as captured — Mailgun: Default not stated; pages mention the US, the EU, United States and Europe. Postmark: its pages as captured do not say.

### Do Mailgun and Postmark have a free plan?

As of 2 Nov 2026, both vendors’ own pages state a free plan. Each product page links the pricing page it was read from.

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Cite as: whats-best.ai, "Mailgun vs Postmark", AI panel comparison, as of 2026-11-06. https://whats-best.ai/compare/mailgun-vs-postmark