StackPostmark
A transactional email service for application email, positioned on inbox deliverability.
What it actually does
Postmark sends the operational email an app depends on: password resets, receipts, notifications, and magic links. Its positioning centers on inbox placement, and in independent testing it has ranked at or near the top among transactional providers.
It separates traffic into message streams, keeping transactional sends isolated from any bulk or broadcast email so a marketing campaign cannot drag down the reputation of your critical mail. Pro tier adds inbound email processing for apps that receive and parse mail.
Pricing is flat and volume-based with no contact-count billing. The tradeoff is a very small free tier and a single large step from free (100/mo) straight to the first paid plan (10,000/mo).
Postmark vs its main rivals
The tools people actually weigh against Postmark: SendGrid, Amazon SES, Mailgun. Same criteria for every column, including where Postmark loses.
 SendGrid | AAmazon SES |  Mailgun | ||
|---|---|---|---|---|
Pricing & access | ||||
| Free tier | Yes100/mo | No60-day trial | NoNo | Yes100/day |
| Starting price | $15/mo | $19.95/mo | $0.10/1k | $15/mo |
Deliverability & sending | ||||
| Independent inbox-placement score | ~83% (top) | ~61% | ~77% | ~71% |
| Message-stream separation | YesYes | YesYes | NoNo | NoNo |
| Inbound email parsing | YesPro tier | YesYes | YesYes | YesYes |
Scaling & limits | ||||
| Overage rate | $1.80/1k | $1.30/1k | $0.10/1k | $1.80/1k |
| Log retention | 45 days | Varies | CloudWatch | 1-5 days |
| Dedicated IP available | YesAdd-on | YesPro plan | YesAdd-on | YesScale plan |
Developer & API | ||||
| REST API | Free | Free | Free | Free |
| Webhooks | Free | Free | Free | Free |
Team & enterprise | ||||
| SSO / SAML | YesEnterprise | YesPro+ | YesAWS IAM | YesEnterprise |
- Top independent inbox-placement scores for transactional email
- Message streams isolate transactional deliverability from bulk sends
- Flat, predictable plans with no contact-count billing
- Free tier of 100 emails/mo is only useful for initial testing
- Basic overage of $1.80 per 1,000 is double Resend's rate
- No annual billing and no middle tier between free and 10,000/mo
Pay less for it
5 ways foundPro at $16.50/mo drops overage to $1.30 per 1,000 and adds inbound processing, usually worth the extra $1.50 over Basic.
100 emails/mo never expires, fine for staging and pre-launch verification.
Above ~50,000 emails/mo Postmark's cost climbs; SES at ~$0.10 per 1,000 is far cheaper for high volume.
Postmark has no yearly prepay plan, so there is no annual-billing saving to capture.
Amazon SES — Roughly 18x cheaper per email if raw cost matters more than turnkey deliverability and you can build your own tooling.
StackTracker tracks what you actually pay for Postmark and every other tool, flags overpayment, and shows the dollars you would save by switching.
Is it the right tool for you
- A missed password reset or receipt would lose you a customer
- You want transactional deliverability walled off from any marketing sends
- You prefer flat plans with no contact-count math
- You need a generous permanent free tier to start → use Resend or Mailgun
- You send very high volume and want the lowest per-email price → use Amazon SES
Track what Postmark and the rest of your stack cost
StackTracker adds up every subscription, plus your hours, so you see the real number.
Prices and limits last verified 2026-07-20.