Side-by-side comparison of free tiers, pricing changes, and stability. Catalogue dates here run to 2026-11-05.
Quick Verdict: Resend offers 3K emails/month free with a modern developer experience. Postmark offers only 100 emails/month free but is legendary for deliverability. For free tier value, Resend wins decisively; for mission-critical transactional email at scale, Postmark has the track record.
Developer-first email API — 3K emails/month free (100/day cap), 3 domains, 1K marketing contacts/month, 5 AI credits, 30-day data retention
Until you verify a domain, Resend sends only from its resend.dev test domain, and only to the email address on your Resend account; mail to anyone else is refused with a 403 error. (From resend.com/docs/knowledge-base/403-error-resend-dev-domain, read 2026-10-20.)
Resend's free plan needs no credit card. (From resend.com/agents, read 2026-10-23.)
Resend launched Inboxes on October 22, 2026. "An inbox sends and receives email at an address on one of your domains." Every plan includes 3 Inboxes. Inboxes can be used by agents to receive tasks and updates. (From resend.com/blog/announcing-inboxes, read 2026-11-06.)
Broadcasts sent through the /broadcasts API or the dashboard do not count against the 3,000 transactional emails a month. Marketing plans are limited by contacts, not email volume. Emails sent or received through an inbox count towards the transactional emails quota. (From resend.com/pricing, read 2026-11-06.)
The default API rate limit is 10 requests per second per team across all API keys. The limit can be increased for trusted senders upon request. (From resend.com/docs/api-reference/rate-limit, read 2026-11-06.)
The API rate limit is the same on every plan and does not change when upgrading. The Batch Email API sends up to 100 emails per request, counting as one request against the limit. (From resend.com/pricing, read 2026-11-06.)
The Free plan has a daily quota of 100 emails, reset at midnight UTC, not a rolling 24-hour window. Paid plans have no daily quota, only a monthly limit. (From resend.com/docs/api-reference/rate-limit, read 2026-11-06.)
Key Differences
Free tier: Resend gives 3K emails/month — 30x more than Postmark's 100 emails/month. For testing and small projects, Resend's free tier is actually usable.
Deliverability: Postmark has built its reputation on industry-leading deliverability with dedicated IP pools and strict anti-spam policies. They reject marketing email entirely.
API design: Resend has a minimal, modern API with React Email support. Postmark has a mature API with message streams, webhooks, and inbound processing.
Philosophy: Postmark is transactional-only (no marketing). Resend is transactional-focused but more flexible with its sending policies.
Pricing Change History
Postmark
No recorded pricing changes for Postmark.
Resend
increasedeffective between 2026-08-19 and 2026-08-20medium impact
The free tier now has a limit of 3,000 emails/month (100/day) and includes 3 domains. Previously 3K emails/month (100/day) and 1 domain. The free tier also includes ticket support, 10,000 automation runs, and 30-day data retention. Source ↗
Our Recommendation
Choose Resend if you want a generous free tier, modern DX with React Email, or you're building a side project that needs to actually send email for free.
Choose Postmark if deliverability is your #1 priority and you're willing to pay for it — Postmark's free tier is effectively a trial, not a production tier.
Resend offers 3K emails/month free with a modern developer experience. Postmark offers only 100 emails/month free but is legendary for deliverability. For free tier value, Resend wins decisively; for mission-critical transactional email at scale, Postmark has the track record.
What is Postmark's free tier?
Postmark offers a Free plan: Transactional email API — 100 emails/month free, never expires, no credit card required. Postmark's free plan needs no credit card. (From https://postmarkapp.com/pricing, read 2026-10-23.)
What is Resend's free tier?
Resend offers a Free plan: Developer-first email API — 3K emails/month free (100/day cap), 3 domains, 1K marketing contacts/month, 5 AI credits, 30-day data retention. Until you verify a domain, Resend sends only from its resend.dev test domain, and only to the email address on your Resend account; mail to anyone else is refused with a 403 error. (From https://resend.com/docs/knowledge-base/403-error-resend-dev-domain, read 2026-10-20.) Resend's free plan needs no credit card. (From https://resend.com/agents, read 2026-10-23.) Resend launched Inboxes on October 22, 2026. "An inbox sends and receives email at an address on one of your domains." Every plan includes 3 Inboxes. Inboxes can be used by agents to receive tasks and updates. (From https://resend.com/blog/announcing-inboxes, read 2026-11-06.) Broadcasts sent through the /broadcasts API or the dashboard do not count against the 3,000 transactional emails a month. Marketing plans are limited by contacts, not email volume. Emails sent or received through an inbox count towards the transactional emails quota. (From https://resend.com/pricing, read 2026-11-06.)
Should I choose Postmark or Resend?
Choose Resend if you want a generous free tier, modern DX with React Email, or you're building a side project that needs to actually send email for free. Choose Postmark if deliverability is your #1 priority and you're willing to pay for it — Postmark's free tier is effectively a trial, not a production tier.