Postmark
by ActiveCampaign LLC
Developer-focused transactional email API with separated transactional and broadcast streams, templates, and fast delivery. Postmark is a transactional email platform founded in 2009 by Wildbit in Philadelphia and acquired by ActiveCampaign in 2022. As of April 2026, Postmark continues to operate as an independent brand within ActiveCampaign, focused on developer-facing transactional email rather than consumer marketing messaging.
Key Facts
| Attribute | Value | As of | Source |
|---|---|---|---|
| Founded | 2009 by Wildbit (acquired by ActiveCampaign 2022) | Apr 2026 | ActiveCampaign press release |
| Parent Company | ActiveCampaign LLC | Apr 2026 | ActiveCampaign |
| 10K Plan | $15/month (10K plan, 10,000 emails) | Apr 2026 | Postmark |
| 100K Plan | $115/month (100K plan) | Apr 2026 | Postmark |
| Message Streams | Separate transactional + broadcast streams on different IP pools | Apr 2026 | Postmark |
| Developer Tier | 100 emails/month free developer tier | Apr 2026 | Postmark |
| Message Log | 45-day message log retention for debugging | Apr 2026 | Postmark |
| Dedicated IP | Dedicated IP $50/month on 300K+ plans | Apr 2026 | Postmark |
About Postmark
Postmark is a transactional email platform founded in 2009 by Wildbit in Philadelphia and acquired by ActiveCampaign in 2022. As of April 2026, Postmark continues to operate as an independent brand within ActiveCampaign, focused on developer-facing transactional email rather than consumer marketing messaging.
The platform separates transactional (one-to-one application email like receipts and password resets) and broadcast (one-to-many announcements) into different message streams on dedicated IP pools. This separation protects transactional deliverability from broadcast sending patterns and is central to Postmark's reputation for fast, reliable inbox placement. The platform provides message templates with Mustachio syntax, inbound email parsing, webhook delivery for events (bounces, opens, clicks, spam complaints), and a message log that retains content for 45 days for debugging.
Postmark uses volume-based pricing. The 10K plan is $15/month for 10,000 emails, 50K plan $55/month for 50,000 emails, 100K plan $115/month, 300K plan $305/month, and higher tiers available. All plans include both transactional and broadcast streams, templates, and full API access. A 100-email/month developer tier is available for testing. Dedicated IPs are $50/month per IP on plans of 300K and above.
Postmark integrates with Zapier, Make, Segment, and provides SDKs for Ruby, Node.js, Python, PHP, Go, Java, .NET, and Elixir. Common use cases include Rails and Django transactional email, SaaS account emails, and as a drop-in SMTP replacement.
Integrations (8)
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Questions About Postmark
Is Postmark worth it in 2026? A detailed review
Postmark scores 7.6/10 in 2026. Developer-focused transactional email with separated transactional and broadcast streams. From $15/mo (10K emails). ActiveCampaign-owned since 2022. Strongest for SaaS transactional delivery.
How much does Mailgun cost in 2026? Pricing breakdown
Mailgun: Foundation $15/mo (10K emails), Growth $35/mo (50K), Scale $90/mo (100K), Enterprise custom. Dedicated IP $60/mo per IP. No permanent free tier. Sinch-owned since 2021.
How much does Postmark cost in 2026? Pricing breakdown
Postmark: Developer free (100/mo), 10K $15/mo, 50K $55/mo, 100K $115/mo, 300K $305/mo. Transactional + broadcast streams on all plans. Dedicated IP $50/mo on 300K+.