Mailgun vs Postmark
An independent, review-free comparison compiled by the SaaSTracker editorial team. Both products are profiled in full, and neither can pay for placement here.
The short answer
Both sides assessedMailgun compared with Postmark
Both do inbound properly, which narrows the comparison to retention, price, and posture. Postmark keeps full message content for 45 days by default and up to 365 days, vets senders so its shared IPs deliver well, and includes support on every plan, at roughly $199 for 150,000 emails. Mailgun keeps 30 days of events on Scale, one day on Basic, and charges about $145. Mailgun's routing rules are more flexible than Postmark's single inbound webhook. Choose Postmark for deliverability and evidence, Mailgun for routing sophistication and price.
Postmark compared with Mailgun
Both offer inbound routing and both are owned by larger parents, Sinch in Mailgun's case. Mailgun is cheaper at volume, has metered email validation built in, and offers more raw infrastructure primitives. Postmark has better shared-IP deliverability, dramatically longer message retention (365 days versus Mailgun's 30 on Scale and 1 day on Basic), and better support. Mailgun's one-day log retention on the entry plan is the detail that sends most small teams to Postmark.
Choose Mailgun if
Development teams that need transactional sending plus real inbound mail routing, particularly applications that receive and process email as a core feature, and anyone who wants list validation and sending from the same vendor.
Choose Postmark if
Software companies and SaaS products that treat transactional email as critical infrastructure and want the highest realistic inbox placement without buying a dedicated IP, especially teams that also need inbound parsing and long searchable message retention.
Side by side
13 attributes| Attribute | Mailgun | Postmark |
|---|---|---|
| Category | ESPs | ESPs |
| Starting price | $15 a month for 10,000 emails (Basic) (free plan available) | $15 a month for 10,000 emails (Basic) (free plan available) |
| Pricing model | Volume-metered on emails sent, with four tiers that differ mainly in included volume, log retention, inbound route allowance, and dedicated IP availability. Email validation is metered separately. | Volume-metered on emails sent, with three feature tiers at the same base volume and different overage rates. No per-seat charge and no contact-based billing. |
| Free plan | 100 emails a day, one inbound route, and one day of log retention. No dedicated IP option. | 100 emails a month with no overages permitted, intended as a developer sandbox rather than a production plan. |
| Free trial | One free month on Foundation and Scale | The free plan never expires and serves as the trial; there is no separate time-limited trial |
| Best for | Development teams that need transactional sending plus real inbound mail routing, particularly applications that receive and process email as a core feature, and anyone who wants list validation and sending from the same vendor. | Software companies and SaaS products that treat transactional email as critical infrastructure and want the highest realistic inbox placement without buying a dedicated IP, especially teams that also need inbound parsing and long searchable message retention. |
| Setup time | Half a day for outbound: add the domain, publish the SPF, DKIM, and tracking DNS records, wait for verification, and drop in the SDK or SMTP credentials. Inbound takes longer because MX changes need planning and routes need designing. | A couple of hours to first production send, plus whatever the sender review takes. Domain verification is DNS records; the SDK or SMTP integration is quick. The account approval step is the only thing that is not instant. |
| Learning curve | Moderate. The sending API is conventional, but Mailgun's route expression syntax, the distinction between sandbox and verified domains, and the interaction between suppression lists and your own database all take a session to understand properly. | Low. The Message Streams concept takes ten minutes to understand and is the only Postmark-specific idea in the product. Templates with layouts are the next thing worth learning because they let non-engineers change email copy without a deploy. |
| Platforms | Web console, REST API, SMTP relay, Inbound routes and webhooks, Official SDKs for 7 languages | Web dashboard, REST API, SMTP service, Inbound webhooks, Official libraries for 7 languages |
| Compliance | SOC 2 Type 2, ISO 27001 through Sinch, GDPR with a data processing agreement, HIPAA arrangements available on enterprise terms | SOC 2 Type 2, GDPR with a data processing agreement, HIPAA-eligible arrangements available on request |
| Founded | 2010 | 2010 |
| Headquarters | San Antonio, Texas, United States, as part of Sinch (Stockholm, Sweden) | Chicago, Illinois, United States (ActiveCampaign); originally Philadelphia, Pennsylvania under Wildbit |
| Ownership | Owned by Sinch AB (STO: SINCH) since December 2021 | Owned by ActiveCampaign since May 2022 |
Strengths and limitations
Mailgun
Strengths
- The best inbound email handling in the category: pattern-matched routes with forward, store, and post actions, priority ordering, full MIME parsing, and retrievable message storage.
- Email Address Validation from the same vendor, which removes a separate tool and a separate contract for list hygiene.
- Volume-based pricing means dormant contacts are free, which is structurally cheaper than any contact-priced marketing platform for product notification traffic.
- Mature API primitives including batch sending with per-recipient variables, versioned templates, tags for reporting, and a queryable Events API rather than only webhooks.
Limitations
- One day of log retention on Free and Basic is close to indefensible, and even Foundation's five days is short against Postmark's 45-day default and 365-day ceiling.
- No marketing capability whatsoever; Sinch's answer to that is Mailjet, a separate product with a separate account and no shared contact base.
- The console is heavier and slower than Resend's, and the overall experience reads as enterprise software rather than a developer tool despite the developer positioning.
- Support quality is a common complaint, particularly on lower tiers, and the enterprise support organisation is slower than a small vendor's.
Postmark
Strengths
- Message Streams make the classic transactional deliverability disaster structurally impossible: marketing mail and application mail never share reputation.
- Consistently excellent inbox placement on shared IPs, achieved by vetting senders and refusing bulk and cold email business rather than by selling everyone a dedicated IP.
- Delivery speed is a genuine differentiator, with customers routinely reporting sub-second arrival on mail that took five to ten seconds elsewhere.
- Inbound parsing with reply-text stripping is a first-class feature, and it is the reason many teams pick Postmark over Resend.
Limitations
- The highest overage rates among the major transactional providers, which makes Postmark progressively less competitive as volume rises past a hundred thousand messages a month.
- No marketing capability at all: no campaign builder, no lists, no segmentation, no automation, no forms. The Broadcast stream is a sending pipe, not a product.
- The free tier at 100 emails a month with no overages is close to useless for evaluation compared with Resend's 3,000.
- Sender vetting at sign-up means account approval is not instant and legitimate senders occasionally get caught in it, particularly anyone whose description of their sending sounds bulk-shaped.
Pricing compared
Mailgun
Volume-metered on emails sent, with four tiers that differ mainly in included volume, log retention, inbound route allowance, and dedicated IP availability. Email validation is metered separately.
- Free$0
- BasicFrom $15
- Foundation$35
- Scale$90
- CustomQuoted
Modelled at this directory's three reference points, Mailgun is mid-market on price and top of the category on inbound capability. A product with 1,000 users receiving three emails each sends 3,000 a month and fits inside Basic at $15, or the free tier if the daily cap allows. Ten thousand users at three emails each is 30,000 sends, still inside Basic at $15 but far better served by Foundation at $35 for the log retention and the inbound routes. Fifty thousand users at three emails each is 150,000 sends, which is Scale at $90 plus roughly $55 of overage, about $145 a month. That sits between Resend at around $80 and Postmark at around $199 for the same volume, and it is roughly ten times Amazon SES. What separates Mailgun from the cheaper options is inbound routing with rules rather than a single webhook, and validation from the same vendor. What separates it from the more expensive ones is that Postmark keeps a year of full message content where Mailgun keeps 30 days of events. Buy Mailgun for inbound; buy something else if outbound is all you do.
Postmark
Volume-metered on emails sent, with three feature tiers at the same base volume and different overage rates. No per-seat charge and no contact-based billing.
- Free$0
- Basic$15
- Pro$16.50
- Platform$18
- High volumeCustom
Modelled the way this directory compares platforms, Postmark is cheap at small scale and expensive at large scale. A product with 1,000 users receiving three notifications each sends 3,000 emails and pays $16.50 on Pro. Ten thousand users at three emails each is 30,000 sends, which is $16.50 plus $26 of overage, about $43. Fifty thousand users at three emails each is 150,000 sends, which is $16.50 plus $182, roughly $199 a month. Resend does that same 150,000 for about $80 and Amazon SES for about $15. What the premium buys is the shared-IP delivery quality that comes from Postmark refusing bulk senders, inbound parsing that Resend does not have at all, a year of searchable message content, and support included on every plan. For a product where a failed password reset is a support ticket and a failed invoice is a dispute, that is defensible up to a few hundred thousand messages a month. Past that, the overage curve stops making sense and you should be negotiating or moving.
Editorial verdict on each
Mailgun
Mailgun is the right purchase when your application receives email as well as sending it. The routing engine, with pattern matching, priority ordering, and forward, store, and post actions, is meaningfully better than the single inbound webhook every competitor offers, and having address validation on the same account removes a whole separate vendor from the list-hygiene problem. The EU sending region is a real advantage for European buyers. The problem is the retention ladder: one day of logs on Basic is not a debugging surface, five days on Foundation is barely one, and only Scale at $90 gets you the 30 days that a support team actually needs. Price it as Foundation or Scale from the start and the value looks reasonable, sitting between Resend and Postmark at around $145 for 150,000 messages a month. Price it as the $15 Basic plan and you will be disappointed the first time a customer asks about an email from last week. If you only send outbound mail, Resend is a better product; if you receive mail, Mailgun is still the one to buy.
Read the full Mailgun profilePostmark
Postmark is the transactional provider to buy when a failed email is a business problem rather than an inconvenience. The Message Streams architecture removes the single most common deliverability disaster, the shared IP pools deliver well precisely because Postmark turns away the senders who would ruin them, and the ability to open a specific message from eight months ago and read what was actually delivered is worth more than most buyers realise until they need it. Inbound parsing with reply-text stripping is a genuine feature advantage over Resend. The honest weaknesses are price and scope: the overage rates are the highest in the category, so a sender doing 150,000 messages a month pays roughly $199 where Resend charges $80 and Amazon SES charges $15, and there is no marketing capability whatsoever, so this is always half of a two-product stack. The ActiveCampaign ownership is a tension to watch rather than a present problem. For a small software business under a few hundred thousand messages a month where password resets and invoices matter, it remains the safest choice in the category.
Read the full Postmark profileMailgun profile last reviewed 2026-08-22; Postmark last reviewed 2026-08-22. Pricing is compiled from public sources and can change without notice. See our methodology.