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Product25 September 2025·3 min read

Bring your own email provider to Paycux

The best signal that a feature is right is not that people ask for it.

Paycux engineering

The best signal that a feature is right is not that people ask for it. It is that people describe their problem in the shape of it before you have built anything.

This piece walks through how we think about it at Paycux, what we have changed our minds about, and where the sharp edges are.

Why we built this

That brings us to why we built this. Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Why it matters

Why it matters deserves its own treatment. Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

  • Choose defaults as carefully as features
  • Settle the name before you ship the thing
  • Ship the smallest honest version
  • Say plainly what the feature does not do

How it works

How it works is where this gets concrete. Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Ship the smallest version that is honest about its limits. A feature that does one thing completely beats one that does five things with an asterisk on each.

Check email delivery status

Check email delivery status is where this gets concrete. Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Ship the smallest version that is honest about its limits.

Example: Configuring Resend as your email provider

That brings us to example: configuring resend as your email provider. Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Step 1: Generate an API key in Resend

That brings us to step 1: generate an api key in resend. Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Step 2: Verify your sending domain

Step 2: Verify your sending domain deserves its own treatment. Defaults are the product. Most people will never open the settings screen, which means the behaviour you chose for them is the behaviour they will experience forever.

Naming is design work. If the team argues about what to call something, the disagreement is usually about what it is, and shipping before that is settled means shipping the confusion to customers.

Where this leaves us

If there is one thing worth taking away, it is that the expensive decisions are the ones made implicitly. Making them on purpose costs an afternoon.

If you are working through the same problem and want to compare notes, the docs cover the mechanics and the console shows the behaviour on your own data.

Everything here, already built

Sign-in, enterprise SSO, directory provisioning, roles and an audit trail behind one API. Start with the quickstart and have a working sign-in this afternoon.

Start selling to enterprise customers

Create an account, point sign-in at Paycux, and get back to the part of the product that is actually yours.