Transactional and bulk email service for developers.
Postmark is a developer-oriented email-delivery service for transactional and bulk email, with REST APIs, SMTP, templates, webhooks, inbound processing, and message-stream controls.
| Plan | Price | Included | Notable |
|---|---|---|---|
| Free | $0.00 /mo | 100 emails/month | Integration testing, No overages |
| Basic | $15.00 /mo | Starting at 10,000 emails/month; $1.80 per 1,000 extra emails | 5 custom sending domains, 45-day data retention, Detailed analytics |
| Pro | $16.50 /mo | Starting at 10,000 emails/month; $1.30 per 1,000 extra emails | Inbound email processing, 10 custom sending domains, Retention up to 365 days |
| Platform | $18.00 /mo | Starting at 10,000 emails/month; $1.20 per 1,000 extra emails | Unlimited custom sending domains, Inbound email processing, Unlimited users |
Checked 2026-08-08 against their pricing page. Vendors change pricing without notice.
Postmark provides application email infrastructure, separating transactional and broadcast message streams and exposing operational email functions through documented APIs and SMTP.
Engineering teams that need application email delivery, inbound parsing, webhooks, templates, and message-level operational controls.
Teams seeking a full marketing-automation suite with audience building and campaign orchestration should look elsewhere; Postmark's retrieved material is centered on transactional and bulk email delivery. Buyers that need to retain full message content longer than 45 days should also plan for a paid retention option.
No curated rival set covers this tool yet, so these are simply other tools in the same architectural layer and product form. Treat it as a starting point, not a shortlist.
Yes. The developer documentation lists REST API operations for email, bulk sending, templates, bounces, servers, message streams, messages, and domains.
The retrieved developer material specifies the X-Postmark-Server-Token header with a Server API Token.
Yes. The pricing page lists inbound email processing and says incoming email can be posted to a webhook as a JSON object.
Yes. The Free tier provides 100 emails/month and the pricing page says it does not expire.
The retrieved developer material states a 10 MB maximum email size including attachments and up to 50 total recipients across To, CC, and BCC.
Yes. SMTP is listed alongside the REST API in the developer documentation and pricing comparison.
This page tells you whether Postmark fits. Cheetah builds and runs the system it goes into — enrichment, sequencing, CRM and the joins between them.
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