As of 2 Nov 2026, the panel rates Mailgun 2/5 and 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.
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.
Read this comparison as one judge. Each weighs the same scores by what they care about.
The Shop Operator
Runs a Shopware shop for kitchen equipment in Germany and Austria with 900 orders a week. Order confirmations, invoices and shipping notices went out through the hosting provider's mail server until a customer found theirs in spam and the support inbox filled up. Wants guided SPF and DKIM set-up a non-specialist can follow, a plugin for the shop, order mail kept apart from the newsletter, and someone to ask when Gmail starts refusing.
Mailgun
This judge's pick
Postmark
Criterion by criterion
Sending API, SMTP & developer experience
Mailgun
Official SDKs for PHP, Node, Python, Ruby, Java, C# and Go, an SMTP relay on ports 25, 465 and 587, batch sending up to 1,000 personalised messages, dynamic templates, scheduled sending, inbound parsing and a sandbox test domain give my developer everything to hook the shop up. We found no public information on idempotency keys, template versioning, an OpenAPI specification or CLI, vendor-maintained framework drivers, rate limits, or a migration guide from our previous provider.
Postmark
The captured pages document a REST API and an SMTP relay with named host and port, official libraries for TypeScript, Node, Python, Ruby, Rails, PHP,.NET and Java maintained by the vendor, framework guides for Laravel, Rails, Express, Django and Craft CMS, a WordPress plugin that overrides wp mail, batch sending up to 500 messages per call, a test-token mode that does not deliver, inbound email parsed to a webhook, a documented CLI and migration guides from SendGrid, Mailgun and others. For my Shopware shop this means sending via SMTP or REST is well covered. We found no public information on idempotency keys or scheduled sending, which is what keeps this just below the top anchors.
Deliverability & sender reputation
Mailgun
SPF, DKIM and DMARC are supported with domain verification and a sandbox test address, dedicated IPs start on Foundation with automated warm-up, hard bounces and complaints are suppressed automatically, and deliverability experts are reachable around the clock — the someone to ask when Gmail refuses. Blocklist monitoring, inbox placement testing and bounce classification sit in the separately priced Optimize suite, and we found no public information on a custom return path, feedback loops, Gmail/Yahoo bulk-sender compliance statements, or order mail and newsletters separated by stream or IP pool.
Postmark
This is what my spam-foldered invoices need: the pages describe SPF, DKIM and DMARC made easy to set up with a free custom Return-Path and DKIM domain, every sender manually vetted one-on-one, transactional and broadcast mail on completely separate infrastructure including IP ranges, and dedicated IPs with Postmark-managed warm-up, blocklist monitoring and feedback loops handled for you. Delivery times are published on a Time to Inbox page and the status page shows real-time delivery metrics. We found no public information on custom tracking domains or an explicit statement of compliance with the Gmail and Yahoo bulk-sender requirements, so I stop one step short of the top.
Message logs, events & webhooks
Mailgun
Logs are searchable by recipient address, event type, tag, message ID and subject, retention is stated per plan up to thirty days on Scale with bodies kept up to seven days, and webhooks for delivered, bounced, opened, clicked, complained and unsubscribed are HMAC-SHA256 signed and retried automatically, backed by an Events API. We found no public information on alerts when bounces or complaints spike, a read-only view for support staff, or viewing the receiving server's raw answer per message; forwarding runs through the Datadog, Splunk and Slack integrations.
Postmark
Webhooks cover delivery, bounce, complaint, open, click and inbound with a fully documented retry schedule, retry-remaining and trace headers, per-event-type health tracking and even a webhook statistics API, while full message content is kept 45 days by default, adjustable from 7 to 365, and an observer role can review history without edit rights. That is exactly what I want when a support colleague has to check why an invoice bounced. The captured pages state plainly that HMAC webhook signatures are not supported, and we found no public information on bounce or complaint spike alerts or on exporting events to an external log tool.
Message data, retention & security
Mailgun
What is stored per message is documented — bodies up to seven days, metadata thirty, recipients hashed — with AES-256 at rest, two-factor login, SAML SSO from Scale, IP access management, a published data processing agreement, and SOC 2 Type II and ISO 27001 statements noting certifications may apply to specific products.
Postmark
What is stored is documented — full message content for 45 days, adjustable from 7 to 365 days, statistics indefinitely — open and link tracking can be switched off per message, encryption at rest is stated, two-factor authentication is on every plan including the free one, IP allowlisting exists, a data-removal API and a published DPA are available, and the data centres are SOC 2 certified. As a German shop two things worry me in the captured pages: the terms state the vendor may view, copy and internally use messaging content to train and improve the service, and outbound TLS is opportunistic only with no customer control over it. We found no public information on SSO or a dashboard audit log.
Reliability, accounts & support
Mailgun
A 99.99% SLA covering API, SMTP and outbound delivery with credits of 5% of the monthly fee per thirty minutes of downtime, capped at half the fee, is published alongside a status page; unlimited users with five permission roles come from Foundation up and support is around-the-clock ticket with phone and chat from Scale. We found no public information on sub-accounts to keep applications apart, mail queueing during incidents, response times per plan, or a Shopware plugin — the integration directory lists WordPress and Shopify and we found no public information on one for Shopware.
Postmark
Redundant data centres in multiple locations with N+2 redundancy and geographic load balancing are described, separate servers with their own limits and up to ten message streams each let me keep order mail apart from anything else, three roles plus per-server permissions including an observer cover my team, support is included at no extra charge, and migration guides exist from named competitors. We found no public information on an uptime SLA, incident history, support response times or mail queueing during outages. A WordPress plugin is documented, but we found no public information on a Shopware plugin, and the terms reserve the right to terminate any account at any time without notice — a real risk when all my order confirmations flow through one pipe.
European sovereignty
Mailgun
An EU region can be selected for sending, a data processing agreement with standard contractual clauses under Swedish law and the Swedish supervisory authority is published, and subprocessors are listed, including US payment and support tools such as Stripe and Zendesk. The Mailgun contract itself runs under Texas law with the San Antonio entity, hosting is on named cloud providers with no location stated for the EU region, and the captured pages don't show whether the EU region covers logs and account data or applies when no choice is made.
Postmark
The contracting entity is AC PM, LLC under Illinois law with ActiveCampaign, LLC as owner, all personal information is stored on AWS and in a data centre near Chicago, and the terms require consent to processing and storage in the United States and other countries; we found no public information on an EU hosting region for messages or logs. On the positive side there is a published DPA with Standard Contractual Clauses under Irish law, an Article 27 EU representative in Kiel, and a sub-processor list with change notification. For my German and Austrian customers this means the whole sending chain, including message content, runs through the US with contractual safeguards rather than EU processing.
Pricing transparency
Mailgun
I can nearly compute my year from public pages: free at 100 emails a day, Foundation at $35/mo with 50,000 emails and Scale at $90/mo with 100,000, overage per thousand from $1.80, $1.30 and $1.10 by plan, an additional dedicated IP at $59/IP/month, log retention per tier, a one-month term with 30-day notice, and prices stated exclusive of VAT. The Optimize suite is priced separately with no figure captured, and whether unused volume carries over is not stated.
Postmark
All four tiers are priced publicly — Free at $0.00/mo with 100 emails, Basic at $15.00/mo, Pro at $16.50/mo, Platform at $18.00/mo — each with a stated extra-email rate per thousand, dedicated IPs at $50/month per IP with no setup fees, custom retention starting at $5/month, DMARC monitoring at $14/month per domain, no rollover of unused volume, and support never charged extra. The pages state that annual plans are not offered yet and high-volume pricing is by contact. We found no public information on the included monthly volume of the paid tiers beyond the entry level or on VAT treatment, which is what keeps the annual cost for my roughly 900 orders a week from being fully computable from public pages alone.
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 — anything else would not be a fair row.
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.
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.