# MailPace (/docs/v/0.6.1/adapters/mailpace)



The MailPace adapter calls the [MailPace send API](https://docs.mailpace.com/reference/send) over `fetch` — no extra dependency. It is the smallest adapter surface in the SDK: addresses, subject, and body only, with recipient lists serialized as comma-separated strings.

<ProviderBadge adapter="mailpace" />

## Configure [#configure]

Create a server token in the MailPace dashboard and verify the sending domain.

```ts title="lib/email.ts"
import { createEmailClient } from "@opencoredev/email-sdk";
import { mailpace } from "@opencoredev/email-sdk/mailpace";

export const email = createEmailClient({
  adapters: [mailpace({ apiKey: process.env.MAILPACE_API_KEY! })],
});
```

<TypeTable
  type="{
  apiKey: {
    description: &#x22;MailPace server token, sent as the MailPace-Server-Token header.&#x22;,
    type: &#x22;string&#x22;,
    required: true,
  },
  baseUrl: {
    description: &#x22;Override the API origin, e.g. for a proxy.&#x22;,
    type: &#x22;string&#x22;,
    default: '&#x22;https://app.mailpace.com/api/v1&#x22;',
  },
  fetch: {
    description: &#x22;Custom fetch implementation for tests or special runtimes.&#x22;,
    type: &#x22;typeof fetch&#x22;,
  },
}"
/>

## Send [#send]

MailPace maps `cc`, `bcc`, and `replyTo` alongside `html`/`text` (sent as `htmlbody`/`textbody`). That is the whole surface — a good fit for sign-in alerts, receipts, and other plain notifications.

```ts
const result = await email.send({
  from: "Acme <hello@acme.com>",
  to: "user@example.com",
  replyTo: "support@acme.com",
  subject: "New sign-in to your account",
  text: "A new sign-in from Berlin, Germany was detected. If this was not you, reset your password.",
});

console.log(result.id); // MailPace message id (`id` or `message_id` in the response)
```

<Callout type="warn" title="No headers, attachments, tags, or metadata">
  MailPace's send endpoint takes none of these, so any of them throws an `EmailValidationError`
  before a request is made. Check your production message shape against the [field support
  matrix](/docs/v/0.6.1/adapters/field-support) before routing through MailPace as a fallback.
</Callout>

## Verify from the CLI [#verify-from-the-cli]

```bash
MAILPACE_API_KEY="..." npx email-sdk doctor --adapter mailpace
```

```bash
MAILPACE_API_KEY="..." npx email-sdk send \
  --adapter mailpace \
  --from "Acme <hello@acme.com>" \
  --to user@example.com \
  --subject "MailPace smoke test" \
  --text "It works" \
  --dry-run
```

Drop `--dry-run` for one real send to confirm the token and verified domain work end to end.