PigeonAtlas: Email That Arrives When It Matters

How we built it

We started from the failure, not the feature list. In the applications we audit, the email path breaks the same few ways: a password reset in spam, a reset stuck behind a newsletter, and nobody able to see what was actually sent. The product had to make each of those impossible or visible.

The first decision was separation. Transactional and bulk mail are dispatched by separate processes that never read each other's work. It is not the cheapest design, and it is the only one in which a broadcast can never delay a reset.

Then identity. Each customer domain gets its own DKIM key, signed under a selector PigeonAtlas controls, and the customer's DNS points only at PigeonAtlas. That one decision means what runs underneath can change without a single customer editing a record, which is exactly what usually keeps teams on a setup they have outgrown.

Then the unglamorous parts that decide reputation. A hard bounce or a complaint suppresses an address permanently, and the check runs at submission, so a dead address never enters the queue. Every message is archived as the exact bytes that went out, so when someone asks whether an email was sent, the answer is a record rather than a guess.

Compatibility came last, on purpose: requests match Resend's format, so moving in is a base URL and a key, and code an AI assistant wrote works unchanged. AI helped throughout, drafting documentation and checking our assumptions. The delivery decisions were ours.

Built with

• Ruby on Rails
• PostgreSQL
• Solid Queue
• SMTP

Questions people ask

Why does a separate queue matter?

Because a newsletter to tens of thousands of people can hold a password reset for minutes. Separate processes mean a reset never waits behind a broadcast.

What is the 'via' label in Gmail?

It appears when the From domain and the signing domain disagree. Signing with a DKIM key on your own domain removes it, which is why every customer gets one.

Can you fix email delivery in our app?

Yes. Domain authentication, separate transactional sending, bounce handling and a record of what was sent are usually a short, contained piece of work.