Resend vs Postmark vs Amazon SES for transactional email: prices and trade-offs
Stack Founder HQ · Updated 18 October 2026 · Auth, email and analytics · How we write
Transactional email covers the messages your app sends automatically: sign-up confirmations, password resets, receipts and notifications. These need to arrive quickly and reliably, so most teams use a dedicated sending service rather than their own mail server. Resend is a newer, developer-focused API. Postmark has specialised in transactional email for many years. Amazon SES is AWS's low-cost, high-volume sending service.
*Prices checked on 18 October 2026 on resend.com/pricing, postmarkapp.com/pricing and aws.amazon.com/ses/pricing. US dollars, excluding tax.*
Prices at a glance
Resend:
| Plan | Price | Emails included | Notes |
|---|---|---|---|
| Free | $0 | 3,000 a month | Daily limit of 100 |
| Pro | $20 a month | 50,000 | Overage $0.90 per 1,000 |
| Pro | $35 a month | 100,000 | Overage $0.90 per 1,000 |
| Scale | $90 a month | 100,000 | Higher limits and features |
Resend's pricing page says it bills monthly only. Overage on Pro is pay-as-you-go, which you switch on in team settings under "Transactional Overages". If it's off and you go over your limit, Resend notifies you instead.
Postmark (prices for the 10,000-email starting tier):
| Plan | Price | Extra emails |
|---|---|---|
| Free | $0 | 100 emails a month, no overages |
| Basic | $15 a month | $1.80 per 1,000 |
| Pro | $16.50 a month | $1.30 per 1,000 |
| Platform | $18 a month | $1.20 per 1,000 |
Postmark's plans can be scaled up to larger monthly volumes using the selector on its pricing page. Larger bundles may work out cheaper than paying overage on the 10,000 tier.
Amazon SES changed its pricing structure in 2026. It now offers plans as well as the older à la carte pricing:
| Price per 1,000 emails (up to 10 million a month) | Fixed monthly fee | |
|---|---|---|
| À la carte | $0.10, plus $0.12 per GB of attachments | None |
| Essentials plan | $0.16 | None |
| Pro plan | $0.22 | $105 per account per region |
| Enterprise plan | $0.23 | $500 per account per region |
AWS says that new SES accounts, and account and region combinations with no metered SES activity since 1 June 2025, start on the Essentials plan from 21 July 2026. You can switch to à la carte at any time. The plans bundle extra features, such as deliverability insights, managed dedicated IPs on higher tiers and email validation. Read the comparison table carefully, because the cheapest option depends on which of those features you would otherwise pay for separately. New AWS customers also get Free Tier credits that can be used on SES.
Worked example: 30,000 emails a month
Using only the published prices above, with small messages and no attachments:
| Service | Calculation | Monthly cost |
|---|---|---|
| Resend Pro | 30,000 is within the 50,000 included | $20 |
| Postmark Basic, 10,000 tier | $15 + 20,000 × $1.80 per 1,000 | $51 (a larger bundle may be cheaper) |
| Postmark Platform, 10,000 tier | $18 + 20,000 × $1.20 per 1,000 | $42 (a larger bundle may be cheaper) |
| Amazon SES à la carte | 30,000 × $0.10 per 1,000 | $3 |
| Amazon SES Essentials | 30,000 × $0.16 per 1,000 | $4.80 |
SES is far cheaper at any volume. What you pay for with Resend and Postmark is the developer experience, the dashboards and the support.
What you get beyond the price
Resend is built for developers. It has a clean API and SDKs, and is closely associated with React Email, an open-source library for building emails with React components. It also offers marketing ("broadcast") email, and its free plan is enough to build and test with.
Postmark focuses on deliverability and visibility. It separates transactional and bulk email into message streams, so marketing sends can't harm the reputation of your password resets. It also includes detailed activity logs, templates and inbound email processing. Its pricing page lists data retention and the number of sending domains by plan.
Amazon SES is infrastructure. You get very low prices and huge scale, but more setup:
- New SES accounts start in the sandbox, where you can only send to verified addresses. You need to request production access before you can send to customers.
- You handle bounces and complaints yourself, usually by connecting SES notifications to your own code.
- Dashboards and logs are more basic unless you pay for the plan features, or build them with other AWS services. Using those services can add to your AWS bill.
Things that matter whichever you choose
- Authenticate your domain. Set up SPF, DKIM and DMARC records for your sending domain. All three services guide you through it, and major mailbox providers expect it.
- Separate transactional from marketing email. Use different streams, subdomains or services, so a marketing campaign can't affect delivery of password resets.
- Watch your bounce and complaint rates. All providers can suspend sending if these get too high.
- Avoid lock-in in your code. Wrap the provider's SDK in your own small email module, so that switching providers later only means changing one file.
Which to choose
- Resend if you want the quickest developer setup, React-based templates, and a predictable $20 a month for up to 50,000 emails.
- Postmark if deliverability, detailed logs and support matter most, and the higher per-email price is acceptable.
- Amazon SES if volume is high or cost is the main concern, and you are comfortable with AWS setup and doing more of the monitoring yourself.
Many products start on Resend or Postmark and only consider SES when sending volumes make the price difference significant.
Sources
- Resend pricing
- Postmark pricing
- Postmark: Message streams
- Amazon SES pricing
- Amazon SES: Request production access