Resend vs Mailgun for Solo Developers

Sending transactional emails is a core requirement for almost every web application. Password resets, welcome emails, invoices, notifications. The question is not whether you need an email service, but which one. Resend and Mailgun both handle the job, but they target different developer experiences. Here is how they compare for solo developers.

Resend Overview

Resend is a modern email API built by the team behind React Email. It launched in 2023 with a developer-first philosophy, offering a clean API, excellent documentation, and first-class support for React Email templates. The pitch is simple: email sending should be as pleasant as using Stripe or Vercel.

The API is minimal and well-designed. Sending an email is a single POST request with a clear JSON payload. SDKs are available for Node.js, Python, Go, Ruby, PHP, and more. React Email integration means you can build email templates using React components and JSX, which is a massive improvement over traditional HTML email templating.

Resend's free tier includes 3,000 emails per month and 100 emails per day. Paid plans start at $20/month for 50,000 emails. Domain verification is straightforward, and deliverability is strong out of the box.

Mailgun Overview

Mailgun has been in the email business since 2010. It is one of the most established transactional email services, used by companies like Lyft, Shopify, and GitHub. It handles sending, receiving, validating, and routing emails at scale.

The API is comprehensive but shows its age compared to newer alternatives. Mailgun supports email sending, inbound email processing, email validation, mailing lists, and detailed analytics. It also offers an SMTP relay for applications that prefer SMTP over API calls.

Mailgun's free tier is limited. You get a sandbox domain for testing but need to enter a credit card and verify a custom domain for production sending. The Flex plan gives you 1,000 free emails for the first month, then charges $0.80 per 1,000 emails. Paid plans start at $35/month for 50,000 emails.

Comparison Table

When to Pick Resend

Resend is the right choice when you value developer experience and modern tooling:

• You want the cleanest API and fastest setup for transactional emails.
• React Email templates are appealing for building maintainable email designs.
• Your email volume is under 3,000/month and you want a real free tier for production use.
• You only need to send emails, not receive or validate them.
• You are building a new project and want modern tooling that matches the rest of your stack.

The free tier being genuinely usable for production is a significant advantage. Many solo developers run their entire email infrastructure on Resend's free plan for months before needing to upgrade.

When to Pick Mailgun

Mailgun makes sense when you need more than just sending:

• You need inbound email processing (parsing incoming emails, email-to-app workflows).
• Email validation is important for cleaning your user list or verifying addresses at signup.
• You want mailing list management built into your email service.
• Detailed analytics and deliverability tools (IP warming, reputation monitoring) matter for your use case.
• You are integrating with a system that expects SMTP and want a battle-tested relay.

Mailgun is also the choice when you need the reliability and reputation of a 14-year-old service. It has processed billions of emails. Edge cases you might encounter have likely been solved already.

Verdict

Resend wins for most solo developers. The developer experience is significantly better, the free tier is more generous for production use, and the React Email integration is genuinely useful if you are in the JavaScript ecosystem. For the typical solo developer use case of sending transactional emails (auth flows, notifications, receipts), Resend covers everything you need with less friction.

Pick Mailgun if you need inbound email processing, email validation, or mailing lists. These are features Resend simply does not offer. If your product involves receiving and parsing emails, or if you need to validate email addresses at scale, Mailgun is the more complete solution. Just be prepared for a slightly rougher developer experience and higher costs at lower volumes.