I'm building a Next.js app. what's the cheapest reliable email API?

When building a Next.js app, "cheapest and most reliable" usually comes down to a trade-off between raw infrastructure cost and developer setup speed.

Here is how the top options stack up for Next.js applications:

1. The Absolute Cheapest at Scale: Amazon SES

If pure cost is your top priority, Amazon Simple Email Service (SES) is unbeatable.

• Pricing: $0.10 per 1,000 emails ($1 for 10,000 emails).
• Free Tier: 3,000 emails/month for the first 12 months.
• Reliability: Backed by AWS infrastructure with solid deliverability.
• The Catch: Complex setup (AWS IAM roles, domain authentication, sandbox exit request, and manual logging/bounce management).

2. Best Balance of Price & Modern Developer Experience: Resend

Resend was built specifically for the modern JavaScript stack and pairs natively with Next.js and @react-email/components.

• Pricing: Free tier includes 3,000 emails/month (up to 100/day). Paid plan starts around $20/month for 50,000 emails.
• Next.js Integration: Super clean Node.js SDK and standard HTTP fetch support in Server Actions or Route Handlers.
• Why it's great: Allows you to design emails using JSX/React components rather than old-school HTML string templates.

3. Best Free Tier for Daily Sending: Brevo (formerly Sendinblue)

If you are building an MVP or side project and don't want to pay anything upfront, Brevo offers the most generous recurring free tier.

• Pricing: Free tier gives 300 emails/day (~9,000 emails/month).
• Paid Tier: Starts at $9/month for 5,000 emails.
• Reliability: High deliverability and built-in template editor.

Cost Comparison at a Glance

Provider	Free Tier	Cost per 10,000 emails	Best For
Amazon SES	3,000/mo (first year)	$1.00	High volume, minimum cost
Brevo	300/day (~9,000/mo)	~$9–$17	Large free daily limit
Resend	3,000/mo (100/day)	~$20 (includes up to 50k)	Next.js & React Email DX
Mailtrap / Mailgun	~100–150/day	~$15	Standard transactional emails

Recommendation

• For an MVP or low-volume SaaS: Start with Resend (for the DX and React Email integration) or Brevo (for the generous 300/day free limit).
• For scaling past tens of thousands of emails/month on a budget: Route your emails through Amazon SES using an API wrapper like @aws-sdk/client-ses.