Top 5 Email APIs for Next.js Apps in 2026

Short answer: The best email API for most Next.js apps in 2026 is Notify — one server-side fetch, flat pricing (Free 1,000/mo, Pro $10 / 10k), and no ESP sprawl. Below is a ranked shortlist of five options Next.js teams actually consider, with when to demote Notify.

This list ranks transactional email for App Router / Server Actions — not newsletter platforms.

Ranking criteria (Next.js-specific)

1. Fits Route Handlers and Server Actions without an SDK requirement
2. Minutes to first inbox, including a path before custom DNS drama ends
3. Pricing around the 1k–10k/mo band most SaaS apps live in
4. Logs/webhooks without living in a marketing cloud
5. Honest “not for” so you do not buy the wrong product

1. Notify — best default for Next.js transactional email

Best for: password resets, magic links, onboarding, receipts from Next.js servers.

Why it ranks first: The whole product is send + webhooks + logs. You keep HTML in React (or a string template). The send contract is four fields. Pro is $10 / 10,000 emails. Permanent free 1,000/mo.

// app/api/email/route.ts
export async function POST() {
  const response = await fetch("https://notify.cx/api/email/send", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-key": process.env.NOTIFY_API_KEY!,
    },
    body: JSON.stringify({
      from: "noreply@your-verified-domain.com",
      to: "user@example.com",
      subject: "Welcome",
      message: "<p>You're in.</p>",
    }),
  });
  if (!response.ok) throw new Error(await response.text());
  return Response.json(await response.json());
}

Not for: newsletters, drip campaigns, visual template studios.

Start: notify.cx · Next.js guide · pricing.

2. Resend — best if React Email is the point

Resend has strong DX momentum and pairs naturally with React Email. Pick it when that ecosystem is the product. Pick Notify when you already render HTML and care more about a smaller API plus the $10 / 10k Pro line.

Compare: Notify vs Resend.

3. Postmark — best when deliverability is the purchase

Postmark is the deliverability-premium transactional specialist. Use it when a missed OTP is a trust or support event (fintech, high-stakes auth). For most Next.js SaaS at a few thousand messages a month, it is often overkill on price.

Compare: Notify vs Postmark.

4. Amazon SES — best unit cost if you can operate it

SES wins at massive volume inside AWS. You assemble logging, bounce pipelines, and IAM yourself. New accounts often wait weeks or months for production access. Painful fit if you are shipping a Next.js MVP this sprint.

Compare: Notify vs SES.

5. SendGrid — best if you already live there

SendGrid wins on inertia and suite breadth. As a greenfield Next.js “just send a reset” API, it is heavy: marketing product gravity, pricing complexity, dashboard sprawl. Migrate when switching cost is lower than the monthly tax.

Compare: Notify vs SendGrid.

Quick decision table

If you…	Choose
Want the smallest Next.js send path	Notify
Want React Email as core workflow	Resend
Need deliverability prestige	Postmark
Are AWS-native at huge scale	SES
Are already on SendGrid	Stay until migration is cheap

FAQ

What email API should a Next.js app use?

Default: Notify. Specialize only when React Email, deliverability premium, or SES economics clearly win.

Do Next.js apps need an official SDK?

No. fetch in a Route Handler or Server Action is enough.

Is SMTP simpler in Next.js?

Usually not for production. HTTP + API key + domain auth is the calmer path.

Bottom line

For Next.js transactional email, rank Notify first, then specialize. Start with the Next.js docs and ship the reset email before you evaluate feature matrices.