Two developer-first email APIs with the same basic shape: a JSON send, an SMTP relay, webhooks and official SDKs. They differ on the free tier, on what $15 to $20 a month buys, and on which languages get a typed client. This page reads both pricing pages and puts the figures side by side; Notix appears as a third column, not as the subject.
Resend's figures were read from its pricing page on 2026-09-12 and Postmark's from its pricing page on 2026-09-13; both dates are repeated under the table. Notix figures come from its own pricing page.
| Criterion | Resend | Postmark | Notix |
|---|---|---|---|
| Free tier | 3,000 emails a month, 100 a day, 1 domain | 100 emails a month on the developer plan | 5,000 emails a month, 200 a day, no card, no end date |
| Entry paid plan | Pro $20 a month | Basic $15 a month | Pro $15 a month |
| Included on that plan | 50,000 emails a month | 10,000 emails a month, then $1.80 per extra 1,000 | 50,000 emails, usage past that metered on the same invoice |
| SMTP relay | Yes, on every plan | Yes, on every plan | Yes, on every plan |
| SDKs | Node, Python, PHP, Ruby, Go, Java, Laravel, Rust, .NET | Node, Python, Ruby, PHP, .NET, and a documented cURL surface | TypeScript, Python, Go, PHP |
| Webhooks | Yes | Yes | Yes, signed, for email, contact and domain events |
| OTP / verification API | No | No | Yes, email and SMS codes |
| Deliverability check before sending | No | No | Yes, a pre-send check API |
| Billing outside USD | USD by card | USD by card | USD by card; naira and shillings from a prepaid wallet |
| SLA | Not stated on the pricing page | Not stated on the pricing page | 99.9% on Pro, credits on the pricing page |
| Prices and limits read from the vendors' own pages: resend.com on 2026-09-12; postmarkapp.com on 2026-09-13. Notix figures are from its own pricing page. | |||
Resend's free plan is 3,000 emails a month with a 100 a day cap and one sending domain. Postmark's developer plan is 100 emails a month. The gap is thirty to one, and it decides who gets to run a small product for nothing: on Resend a side project with a few hundred sign-ups a month never pays; on Postmark it pays $15 from the first real month. Both free tiers are meant for testing the integration first, and both work for that.
Postmark Basic is $15 a month for 10,000 emails, then $1.80 for each extra 1,000. Resend Pro is $20 a month for 50,000. At 10,000 emails Postmark is $5 cheaper; at 50,000 Postmark Basic reaches about $87 against Resend's $20, unless you move up a Postmark plan. The lines cross a little under 13,000 emails a month. Below that, Postmark is the cheaper paid plan; above it, Resend is, and the gap widens with volume.
Both take a JSON body with from, to, subject and html and return a message id, and both offer an SMTP relay on every plan, so a framework mailer or an application you would rather not touch can send without the API. A plain transactional send moves between the two after a client swap and a credential change; neither locks you in at the send call. Where they differ is around the send, not in it.
Resend lists Node, Python, PHP, Ruby, Go, Java, Laravel, Rust and .NET. Postmark lists Node, Python, Ruby, PHP and .NET, with a documented cURL surface for everything else. Node, Python, PHP, Ruby and .NET teams get a typed client from both; Go, Java and Rust teams get one from Resend only. For the languages both cover, the clients are the same shape and the choice will not rest on them.
Both deliver event webhooks for delivery, bounce and complaint events, so a bounced address can be marked in your own database. Neither offers a one-time-code API: generating, storing, expiring and checking a code is yours to build on either. Neither offers a deliverability check you can call before a send. On these two rows the services are equal, and equally empty.
Both bill in US dollars by card. Neither pricing page states an SLA figure for the plans compared here, so this page does not put one in either vendor's mouth. If a written uptime commitment or a bill in another currency is a requirement, neither of the two headline services meets it on the plans read here.
On the same criteria: Notix Free is 5,000 emails a month and 200 a day with no card and no end date, so its free tier sits with Resend's rather than Postmark's. Pro is $15 a month for 50,000 emails, with usage past that metered on the same invoice, which undercuts both paid plans at 50,000. SMTP, webhooks and SDKs for TypeScript, Python, Go and PHP are on every plan. The rows where it differs are the ones both headline services leave empty: a verification API for one-time codes by email or SMS, a deliverability check you call before a send, a 99.9 percent commitment on Pro, and billing from a naira or shilling wallet as well as by card.
Same free tier shape, $5 a month less at 50,000 emails, plus OTP and deliverability APIs and naira or shilling billing.
AlternativesFive times the included volume at the same $15, with the marketing side and an OTP API in the same account.
ComparePricing, sending API, deliverability tooling, SDKs and billing regions, side by side with a read date.
CompareTen thousand emails for $15 against fifty thousand, and the one thing Postmark has that Notix does not claim.
CompareEvery vendor in one table with read dates, and a straight answer to which transactional email API a startup should pick.
NotixA free plan with no card, and Pro at $15 a month for 50,000 emails. Only sent volume is metered.
5,000 emails a month on Free, no card, no end date. Pro is $15 for 50,000 emails.