---
title: DKIM
description: Sign outgoing messages with RSA-SHA256 or Ed25519-SHA256.
icon: KeyRound
source: "src/dkim.ts"
---

<Callout title="The one rule">Keep the private key out of source control and publish the matching DNS record before sending.</Callout>

<Steps><Step title="Sign a raw message">

```ts
import { signDKIM } from "sently/dkim";

const result = await signDKIM(rawMessage, {
  domainName: "example.com", keySelector: "2024", privateKey: process.env.DKIM_PRIVATE_KEY!,
});
```

</Step></Steps>

SMTP configuration also accepts `dkim`.

<Accordions><Accordion title="Which keys are supported?">RSA keys of at least 1024 bits and Ed25519 keys are supported.</Accordion></Accordions>

<Cards><Card title="SMTP transport" href="/docs/transports/smtp" /></Cards>