Transactional-email specialist with deliverability obsession and clean API
Postmark is the principled choice for transactional email. The company refuses to send marketing email through their transactional infrastructure — separate accounts, separate IP pools, separate everything — which is the technical reason their deliverability beats most competitors. The pricing is per-email rather than per-volume tier, which means cost predictability. Smaller feature surface than SendGrid (no native marketing campaign tools), but the focus is the point. Best fit: SaaS apps where transactional email reliability matters more than feature breadth.
Best deliverability we have measured in 10 years of SaaS.
Migrated from Mailgun for deliverability reasons in 2023. Our user signup confirmation open rate went from 78% to 94%. Postmark refuses to send marketing email on their infrastructure and the deliverability gap is the result.
Linear pricing. No tier surprises.
SendGrid pricing has cliffs (free → essentials → pro). Postmark is $1.25 per 1K, always. I can predict next month bill exactly. That clarity has more value than I expected.
Need marketing campaigns? Integrate something else.
Postmark for transactional, Resend or Customer.io for marketing. Two integrations is the cost of the design philosophy. Most teams I know have made peace with it.
Methodology
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