Postmark is completely free with 4 features included. No paid tiers offered, making it perfect for budget-conscious users.
By design. Marketing emails receive spam complaints, which degrade IP reputation. Postmark keeps its infrastructure transactional-only to maintain the highest possible deliverability for your important emails. Use a separate service (SendGrid, Mailchimp) for marketing.
Both focus on developer experience. Postmark has a longer track record, proven deliverability metrics, and dedicated transactional infrastructure. Resend has a more modern API design, React email template support, and is growing fast. For proven reliability, Postmark. For cutting-edge developer experience, Resend.
Postmark monitors sending patterns and will flag or suspend accounts that send bulk marketing content. Their terms of service explicitly prohibit marketing email. They're serious about this — it's how they maintain deliverability for all customers.
SES is roughly 10x cheaper per email. Postmark provides better deliverability, faster delivery, a much cleaner API, and real-time support. For critical transactional emails where inbox placement and speed matter, Postmark's premium is justified. For high-volume notifications where some spam folder delivery is acceptable, SES is more cost-effective.
It's completely free — no credit card required.
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Last verified March 2026