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
pricing
| Attribute | Value | As of | Source |
|---|---|---|---|
| Postmark pricing (July 2026) | Postmark pricing (verified July 2026): Free $0 (100 emails/mo, hard cap) plus three paid tiers that all start at 10,000 emails/mo and differ mainly by overage rate — Basic $15/mo ($1.80/1,000 overage), Pro $16.50/mo ($1.30/1,000, "Most Popular"), Platform $18/mo ($1.20/1,000). Transactional and broadcast streams are on every plan; dedicated IPs are $50/mo each, DMARC monitoring $14/mo per domain. Billed monthly on volume (no annual pricing). | Jul 2026 | Postmark pricing |
General
| 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) | Jul 2026 | Postmark Pricing |
| 100K Plan | No fixed 100K plan as of July 2026; 100K on Pro ≈ $133.50/month ($16.50 base + $1.30 per 1K overage) | Jul 2026 | Postmark Pricing |
| Message Streams | Separate transactional + broadcast streams on different IP pools | Jul 2026 | Postmark Message Streams |
| Developer Tier | 100 emails/month free developer tier | Jul 2026 | Postmark Pricing |
| Message Log | 45-day message log retention for debugging | Jul 2026 | Postmark Pricing |
| Dedicated IP | Dedicated IP from $50/month per IP for 300K+/month senders (Pro plan or higher, as of July 2026) | Jul 2026 | Postmark Pricing |
Pricing Plans
Free
Free developer plan; does not expire. No overage — hard cap.
- ✓Full REST API + SMTP access
- ✓Transactional + broadcast message streams
- ✓Sandbox mode for testing
- !100 emails/month (hard cap, no overage)
Basic
Month-to-month only (Postmark offers no annual plans); $15/mo includes 10,000 emails, extra emails $1.80/1,000
- ✓REST API + SMTP sending
- ✓Templates and event webhooks
- ✓Shared IP pools with managed reputation
- !10,000 emails/month included
- !Overage $1.80 per 1,000 emails
- !45-day activity/log retention
Pro
Month-to-month only (no annual plans); $16.50/mo includes 10,000 emails, extra emails $1.30/1,000
- ✓Everything in Basic at a lower overage rate
- ✓Dedicated IP add-on eligible (from $50/mo, 300K+ emails/mo)
- ✓Marked 'Most Popular' by Postmark
- !10,000 emails/month included
- !Overage $1.30 per 1,000 emails
Platform
Month-to-month only (no annual plans); $18/mo includes 10,000 emails, extra emails $1.20/1,000
- ✓Lowest overage rate of the three paid tiers
- ✓Dedicated IP add-on eligible (from $50/mo, 300K+ emails/mo)
- ✓Full feature set incl. webhooks, templates, stats API
- !10,000 emails/month included
- !Overage $1.20 per 1,000 emails
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 pricing (restructured, July 2026) has three tiers — Basic $15/month, Pro $16.50/month, and Platform $18/month — each including 10,000 emails, with metered per-1,000 overage above (100K emails on Pro comes to about $133.50/month). 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
What does the Resend free tier include in 2026?
As of July 2026, the Resend free tier includes 3,000 emails/month, 100 emails/day, one verified domain, 30-day email log retention, and basic webhooks. It is intended for development, testing, and very small production sends; teams typically upgrade to the $20/month Pro plan (50,000 emails/month, multiple domains, audiences) once they exceed the 100-emails/day cap. The next step up is Scale at $90/month (100,000 emails, dedicated IP available). Resend's appeal is developer experience — React email templates and modern SDKs — rather than the free tier being the largest in the category.
How do you migrate from SendGrid to Resend in 2026?
A SendGrid-to-Resend migration in 2026 follows five steps: verify domains in Resend, port templates (Resend recommends React Email), swap the API client in code, run dual-send for a verification window, and update DNS to point all sending traffic to Resend. Most production migrations take 1-2 weeks end to end.
What's the difference between Resend, SendGrid, and Postmark?
Resend is a React-template developer-first email API from 2023 with 3,000 free emails/month and $20/month for 50K. SendGrid is the high-scale market leader from 2009 (Twilio) with marketing plus transactional from $19.95/month. Postmark is the deliverability specialist from 2010 (ActiveCampaign) for transactional-only at $15/month for 10K.
What are the best Postmark alternatives in 2026?
As of April 2026, the leading Postmark alternatives are SendGrid (largest email API by volume), Mailgun (developer-focused infrastructure), Amazon SES (cheapest at scale), Resend (modern developer experience), and Loops (transactional plus marketing for SaaS). Selection depends on deliverability priorities, pricing model, and marketing needs.