# Adapters (/docs/adapters)



Email SDK ships with fifteen adapters. Import only the adapter you use.

Every adapter is stable in the same sense: it maps the fields it supports and throws a validation error for fields the provider API cannot represent. Use the <a href="/docs/adapters/field-support">SDK field support guide</a> before choosing fallback routes.

<ProviderGrid />

## Import pattern [#import-pattern]

```ts
import { createEmailClient } from "email-sdk";
import { resend } from "email-sdk/resend";
import { smtp } from "email-sdk/smtp";

const email = createEmailClient({
  adapters: [
    resend({ apiKey: process.env.RESEND_API_KEY! }),
    smtp({
      host: process.env.SMTP_HOST!,
      auth: {
        user: process.env.SMTP_USER!,
        pass: process.env.SMTP_PASS!,
      },
    }),
  ],
  fallback: ["smtp"],
});
```

## Adapter groups [#adapter-groups]

| Group          | Adapters                                                                        |
| -------------- | ------------------------------------------------------------------------------- |
| Popular APIs   | Resend, Postmark, SendGrid, Mailgun, MailerSend, Brevo, Mailchimp Transactional |
| Infrastructure | SparkPost, Mailtrap, Scaleway, ZeptoMail, MailPace                              |
| Product-led    | Loops, Plunk                                                                    |
| Transport      | Built-in SMTP                                                                   |