Why We Built RelayPost

The problem we kept hitting

Every developer who's integrated a transactional email service knows the pattern. You sign up, get an API key, send a test email, and think "this is easy." Then reality sets in.

DNS records that take three support tickets to get right. Bounce handling that requires you to build your own webhook processor. Dashboards designed for marketers, not engineers. Pricing that doubles when you cross an invisible threshold. Documentation that was last updated two years ago.

We lived this cycle across SendGrid, Mailgun, Postmark, and SES. Every time, we ended up building the same glue code, the same monitoring, the same workarounds. The email providers gave us a pipe to push messages through, but everything around it — the intelligence — was left to us.

What "AI native" actually means

AI native isn't a marketing label we slapped on after the fact. It's a design decision that shaped RelayPost from the first commit.

Most email platforms were built in 2012-2015 and have been bolting on features ever since. Their architecture assumes a human operator is watching dashboards, manually adjusting sending patterns, and reacting to deliverability issues after they happen.

We built RelayPost with the assumption that intelligence should be embedded in the infrastructure itself:

• Bounce classification happens automatically — hard bounces suppress immediately, soft bounces retry with exponential backoff, and the system learns which patterns are transient vs. permanent
• Domain warmup isn't a manual schedule you follow from a blog post — it's a system that monitors reputation signals and adjusts sending volume in real time
• Deliverability monitoring doesn't wait for you to check a dashboard — anomalies trigger alerts before they become problems
• Content analysis catches spam-trigger patterns before the email leaves your infrastructure, not after it lands in a spam folder

The difference isn't that we use AI somewhere in the stack. It's that the entire platform was designed around the idea that email infrastructure should be self-aware and self-correcting.

Built for developers, not marketers

RelayPost is a transactional email platform. We don't do marketing campaigns, newsletter builders, or drag-and-drop template editors. That's a deliberate choice.

Transactional email — password resets, order confirmations, security alerts, onboarding sequences — has different requirements than marketing email. It needs to be fast, reliable, and programmatic. The developer is the user, not the marketing team.

That means:

• A REST API and SMTP relay that work the way developers expect
• Documentation written for engineers, with real code examples in every language
• A dashboard that shows delivery metrics, not campaign analytics
• Pricing based on volume, not features hidden behind enterprise tiers
• A developer-first internal toolchain — because we eat our own dog food

The stack

We're transparent about what RelayPost runs on because we think it matters. Our stack choices reflect the same philosophy as the product: modern, fast, no legacy baggage.

• Runtime: Bun — not Node.js. Faster startup, native TypeScript, built-in test runner
• Framework: Astro with server-side rendering for the dashboard and static pages for the public site
• Database: PostgreSQL with Drizzle ORM — type-safe queries, zero runtime overhead
• Background processing: purpose-built job queue for bounce handling, webhook delivery, and analytics
• API: a typed internal API for the dashboard + a versioned REST API for external developers — each optimized for its consumer

We wrote more about the technical decisions in Building an Email API with Bun, Astro, and PostgreSQL.

What's next

RelayPost is live and sending email. We're focused on three things right now:

1. Expanding the public REST API to cover every operation available in the dashboard
2. Building out the AI-powered deliverability engine — predictive reputation scoring, automated warmup, content optimization suggestions
3. Growing the documentation and guide library so developers can self-serve without filing support tickets

If you're tired of email infrastructure that treats you like an afterthought, give RelayPost a try. Setup takes about five minutes.