Resend

What Resend actually is

Resend is a transactional email API aimed squarely at developers. Your application calls a REST endpoint (or uses an official SDK, or relays over SMTP), and Resend handles the parts of email that are miserable to build yourself: DKIM/SPF/DMARC authentication, bounce and complaint handling, delivery tracking, and inbox placement. It is not a marketing suite bolted onto an SMTP relay — it is an email-sending product built by people who care about how unpleasant email development has historically been.

The origin story is unusually well documented. Zeno Rocha and Bu Kinoshita wrote the first lines of code in August 2022, signed a first paying customer in September, got into Y Combinator's Winter 2023 batch, open-sourced React Email in December 2022, and incorporated the company in January 2023. Jonni Lundy joined the founding team. A $3 million seed followed in mid-2023, and an $18 million Series A led by Andreessen Horowitz came later. That timeline matters for a comparison site: Resend is a young company, roughly three years old as a business, competing against SendGrid, Mailgun, and Postmark products that have been sending mail for a decade or more.

The headline differentiator is React Email: a component library for building HTML email templates that render correctly across clients, which is the single most tedious problem in the field. You compose an email as JSX, it compiles to HTML that renders reliably, and the same components work in your preview tooling and in production. For React and Next.js teams this is a genuine productivity argument, not marketing decoration. For teams on other stacks the API and SMTP relay work fine, but you lose the marquee feature.

The product surface has expanded since launch: transactional sending, marketing emails (added January 2024), broadcasts via API, inbound email, automations with a monthly run allowance, and web-facing "inboxes". We will focus on the transactional core, which is what most readers are buying.

Pricing: what you really pay

The pricing page is a model of clarity, and the numbers below come straight from it. The Free plan sends 3,000 emails per month, capped at 100 per day, from up to 3 verified domains, with 3 inboxes, 30-day data retention, and 10,000 automation runs per month. No credit card, no overage — once you hit a limit, sends simply fail until the window resets.

Pro starts at $20 per month for 50,000 emails (no daily cap, 10 domains, 5 webhook endpoints), with a second Pro step at $35 per month for 100,000. Overage, when enabled, is $0.90 per 1,000 emails. The Scale ladder runs $90 per month for 100,000 emails, $160 for 200,000, $350 for 500,000 ($0.70 per 1,000 effective), $650 for 1,000,000 ($0.65 per 1,000), $825 for 1,500,000, and $1,150 for 2,500,000 ($0.46 per 1,000). Enterprise is custom, aimed at customers sending in the millions per month, and is where SLA guarantees, dedicated success management, and custom retention live.

Add-ons are few and plainly priced: 100 extra domains for $20 per month on Pro and Scale, dedicated IPs at $30 per month (Scale customers sending more than 3,000 emails per day), and extra inboxes at $1 per month each on paid plans. Marketing email is priced separately by contacts: free up to 1,000 contacts, then Pro marketing tiers from $40 per month for 5,000 contacts upward. Automations include 10,000 runs per month on all plans, then $0.0015 per run on paid tiers (the free plan keeps the 10,000 with no overage). Self-serve plans are monthly-only; there is no annual discount.

Two counting rules change your bill and deserve attention. First, recipients, not requests: one message addressed to three people counts as three emails, and both sent and received messages count toward quotas. Second, overage is opt-in — if you leave it off, sends stop at the cap instead of generating a surprise invoice. We consider both policies honest; the opt-in overage in particular is the right default and more vendors should copy it.

How does that compare on price-performance? At 50,000 transactional emails per month, $20 is competitive with Postmark-class providers and meaningfully cheaper than many established alternatives at the same volume. The free plan's 100-per-day cap is the constraint that pushes growing apps to Pro — a busy signup day can exhaust it — but 3,000 per month at zero cost is enough to build and test on.

Performance & infrastructure

Resend runs on Amazon Web Services, which it lists first among its sub-processors as "third party hosting and sending provider". Crucially, sending region and data residency are separate concepts in its architecture, and its docs are explicit about this. You can dispatch mail from four AWS regions: North Virginia (us-east-1), Ireland (eu-west-1), São Paulo (sa-east-1), and Tokyo (ap-northeast-1). You can even assign different subdomains to different regions and route accordingly.

But region selection controls only where mail is routed and sent from. All account data — email metadata, logs, API records, message content — is stored in the United States regardless of the sending region you choose. Resend states this directly: picking eu-west-1 dispatches mail from Ireland but leaves the data in the US, and there is no setting that moves stored data to the EU. For latency, the region picker works well. For GDPR data-residency requirements, it does not solve your problem, and we would rather you hear that from us than from a compliance audit.

On the compliance side generally, Resend does better than its youth suggests: SOC 2 Type II, GDPR compliance (documented since 2024), MFA, granular API key permissions, and DKIM/SPF/DMARC handled for you. Email and log data is retained for 30 days on all plans, with deletion within 90 days of account termination and 7-day backups. A 30-day retention ceiling on every self-serve tier is short if you use logs for dispute resolution or debugging; Enterprise plans offer flexible retention.

Deliverability is the invisible performance metric, and it is where being a layer on shared AWS infrastructure cuts both ways. The good part: AWS's sending infrastructure is mature, and authentication is handled correctly out of the box. The part to weigh: shared sending IPs mean your reputation neighbors on infrastructure you do not control, which is why the dedicated IP add-on exists for higher-volume senders. We have not run our own deliverability tests against Resend (that is not part of our benchmark suite — see /benchmarks), so we will state the structural facts and leave measured inbox-placement claims to people who publish their methodology.

Where it falls short

Youth is the first gap. Resend's track record as a business is about three years long. The established players have survived a decade of spam-filter churn, major outages, and deliverability crises; Resend has not yet been tested by that much time. Its public incident history is short partly because its history is short.

Then the data-residency issue above: US-only storage of account data, with the sending-region toggle offering latency benefits but not jurisdictional ones. If you are a European company handling EU personal data and your DPO wants EU-at-rest guarantees, Resend is not the answer today — a point EU-focused competitors make at length, and they are right about the facts even if they are not neutral about them.

Retention is capped at 30 days on self-serve plans. SMTP relay exists but brings no extra retention. There is no self-serve uptime SLA — a 99.99% SLA is advertised for Enterprise plans only, negotiated with sales. The daily 100-email cap on Free is stricter than some competitors' free tiers, and the recipient-counting rule can surprise teams that blast multi-recipient notifications. Finally, advanced deliverability tooling (custom IP warming programs, granular reputation controls) is thinner than at the largest incumbents.

Who should pick this

Our pick for product teams on modern stacks — especially React and Next.js — sending transactional email at volumes from zero to a few million per month. Password resets, receipts, notifications, magic links: this is the workload Resend is built for, and the developer experience of building those templates with React Email is the best we have seen in this category. The transparent pricing ladder and opt-in overage also make it the choice when you want to predict the bill without a spreadsheet.

We would steer elsewhere if you need EU data at rest, if your volume is high enough that dedicated infrastructure and custom reputation management dominate the decision (talk to the big incumbents and Resend's Enterprise team in parallel), or if you want a decade-long track record on the invoice you are signing. For marketing-heavy use cases, note that Resend now has a marketing product, but the transactional plans are the reason to pick it; compare /category/email-server-hosting options carefully if campaigns are your core workload.

Key takeaways

• Developer-first transactional email API: REST, SMTP relay, official SDKs, and React Email for template building; the React integration is the standout feature.
• Transparent pricing: Free 3,000 emails/month (100/day cap), Pro $20/month for 50,000, Scale from $90/month up to $1,150/month for 2.5M, overage opt-in at $0.90 per 1,000.
• Four AWS sending regions (Virginia, Ireland, São Paulo, Tokyo), but all account data is stored in the US regardless — sending region is not data residency.
• SOC 2 Type II, GDPR documentation, and free DKIM/SPF/DMARC handling; 30-day data retention on all self-serve plans.
• Young company (incorporated January 2023, YC W23): great product, shorter track record, and uptime SLA only on Enterprise.
• Our pick for React/Next.js teams sending transactional mail; wrong fit when EU data residency or long-term deliverability pedigree is the priority.

Sources

• https://resend.com/pricing
• https://resend.com/docs/knowledge-base/account-quotas-and-limits
• https://resend.com/docs/dashboard/domains/regions
• https://resend.mintlify.dev/docs/dashboard/domains/regions
• https://resend.com/handbook/company/how-we-got-here.md
• https://resend.com/blog/y-combinator
• https://zenorocha.com/resend-raises-3m-seed-round
• https://zenorocha.com/resend-raises-18m-series-a
• https://sendfox.com/compare/resend-pricing
• https://21cloudbox.com/support/resend-china.html
• https://osdomains.com/alternatives/resend-alternative
• https://tratto.email/en/compare/resend