Decision guide / 01
Resend vs Postmark for a New SaaS: Costs at 1,000 and 10,000 Emails
For your first SaaS, the useful question is how many emails you need on your busiest day. A small monthly total can still outgrow a free plan.
By AIIndieKit editorial · Official information checked · USD, monthly billing
The date above records our source check. This guide is based on documentation and calculations, not provider delivery tests.
Our editorial judgment
Start with volume. Check the peak.
- 1,000 emails/month, at most 100 on any UTC day: Resend Free fits at $0. Postmark requires its $15 Basic plan.
- 1,000 emails/month, but 250 on launch day: Resend Pro is $20. Postmark Basic is $15, provided your account is approved.
- 10,000 emails/month: Postmark Basic costs $5 less than Resend Pro. Resend Pro includes more monthly headroom.
This is a cost-and-limits comparison based on documentation. We have not run a head-to-head delivery or inbox-placement test.
Calculated from public plans
What would you pay?
One SaaS, one sending domain, one recipient per message, outbound transactional email only. Accounts are eligible to send. No inbound usage, taxes, extras, discounts, marketing campaigns, or migration costs.
1,000 / month · peak 100 / day
- Resend
- $0 / moFree
- Postmark
- $15 / moBasic
1,000 / month · peak 250 / day
- Resend
- $20 / moPro
- Postmark
- $15 / moBasic
10,000 / month · peak 500 / day
- Resend
- $20 / moPro
- Postmark
- $15 / moBasic
Formula: choose Free only if the monthly allowance and every applicable daily limit fit; otherwise use the lowest listed paid plan that fits. All three scenarios stay inside the paid allowances, so overage is $0. At 10,000: $20 − $15 = $5/month.
A 1,000-email month averages about 33/day over 30 days. That average does not make a 250-email launch day fit Resend Free. Queueing tomorrow is also a poor workaround for time-sensitive login or reset emails.
Official facts
The limits behind the table
Resend
Free includes 3,000/month and 100/day; Pro is $20/month for 50,000, without a daily email quota. Free resets at midnight UTC. Inbound messages and each To/CC/BCC recipient consume quota. API rate limits still apply to paid plans.
Postmark
Free includes 100/month. Basic starts at $15/month for 10,000; there is no smaller paid tier. Basic lists no daily cap. Extra Basic emails are $1.80 per 1,000. No daily cap does not remove account review, monthly allowances, or anti-abuse restrictions.
A plan is not permission to send.
Resend: Production sending requires a domain you own and have verified. A successful setup test does not demonstrate inbox placement. Confirm the account can send your intended messages before routing real users through it.
Postmark: New accounts undergo manual approval. Pending accounts can send only to verified domains they own. You also need a verified sender address or domain. Paying for Basic should not be treated as automatic approval.
For either provider: configure sender authentication, handle rejected requests and bounces, and test your own signup/reset flow. These tasks are implementation advice, not results from a test we performed for this comparison.
Our editorial judgment
Choose for your actual launch.
Choose Resend Free when your real daily peak stays within 100 and $0 matters. Consider Postmark Basic when you need 1,000–10,000/month and a peak above 100: its listed subscription is cheaper than Resend Pro for these workloads. Consider Resend Pro if its integration suits you or the included 50,000/month capacity matters. We have not benchmarked either integration.
If you are still testing with at most 100 emails/month, both free plans can fit. Do not upgrade only because a comparison recommends a paid plan.
Ordinary official links. No paid placement or approved affiliate partnership is claimed. A visit or click is not a purchase.
Method, scope & sources
Checked 2026-09-30 against official pricing and documentation. “Official facts” summarizes those pages; the cost table is our calculation; recommendations are editorial judgment. Prices can change. This guide covers transactional sending up to 10,000/month, not marketing-email pricing or deliverability rankings.
- Resend — transactional pricing
Free and Pro prices, included volume, daily limits · checked 2026-09-30
- Resend — account quotas and limits
UTC daily reset; recipient and inbound counting; API rate limits · checked 2026-09-30
- Resend — verified domains
Owned, verified domain required for production sending · checked 2026-09-30
- Postmark — pricing
100/month free; Basic 10,000/month at $15; no daily cap · checked 2026-09-30
- Postmark — account approval
Manual review; pending accounts restricted to verified domains · checked 2026-09-30
- Postmark — sender signatures
Verified sender address or domain before sending · checked 2026-09-30
Before deciding, write down your monthly volume, busiest UTC day, number of recipients per message, and whether you receive inbound email. Those four details are more useful than a generic “best email service” label.