Advanced Nodemailer configuration#

The Nodemailer provider supports OAuth2 authentication, connection pooling, DKIM signing, and rate limiting. Each scenario adds specific keys to `providerOptions` on top of a standard SMTP configuration.

This page covers production scenarios for the community @strapi/provider-email-nodemailer package that can be used with the Email feature. For basic provider installation and SMTP setup, see Configuring providers.

:::info Supported providers
For the full list of supported providerOptions, refer to the .
:::

OAuth2 authentication#

For services like Gmail or Outlook that require OAuth2 instead of a password:

module.exports = ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: 'smtp.gmail.com',
        port: 465,
        secure: true,
        // highlight-start
        auth: {
          type: 'OAuth2',
          user: env('SMTP_USER'),
          clientId: env('OAUTH_CLIENT_ID'),
          clientSecret: env('OAUTH_CLIENT_SECRET'),
          refreshToken: env('OAUTH_REFRESH_TOKEN'),
        },
        // highlight-end
      },
      settings: {
        defaultFrom: env('SMTP_USER'),
        defaultReplyTo: env('SMTP_USER'),
      },
    },
  },
});

export default ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: 'smtp.gmail.com',
        port: 465,
        secure: true,
        // highlight-start
        auth: {
          type: 'OAuth2',
          user: env('SMTP_USER'),
          clientId: env('OAUTH_CLIENT_ID'),
          clientSecret: env('OAUTH_CLIENT_SECRET'),
          refreshToken: env('OAUTH_REFRESH_TOKEN'),
        },
        // highlight-end
      },
      settings: {
        defaultFrom: env('SMTP_USER'),
        defaultReplyTo: env('SMTP_USER'),
      },
    },
  },
});

Connection pooling#

Use connection pooling to reuse SMTP connections and improve throughput when sending many emails:

module.exports = ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 465,
        secure: true,
        // highlight-start
        pool: true,
        maxConnections: 5,
        maxMessages: 100,
        // highlight-end
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

export default ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 465,
        secure: true,
        // highlight-start
        pool: true,
        maxConnections: 5,
        maxMessages: 100,
        // highlight-end
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

DKIM signing#

Add DKIM signatures to improve deliverability and authenticate outbound mail:

module.exports = ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 587,
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
        // highlight-start
        dkim: {
          domainName: 'example.com',
          keySelector: 'mail',
          privateKey: env('DKIM_PRIVATE_KEY'),
        },
        // highlight-end
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

export default ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 587,
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
        // highlight-start
        dkim: {
          domainName: 'example.com',
          keySelector: 'mail',
          privateKey: env('DKIM_PRIVATE_KEY'),
        },
        // highlight-end
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

Rate limiting#

Limit the number of messages sent per time interval to avoid triggering spam filters:

module.exports = ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 465,
        secure: true,
        pool: true,
        // highlight-start
        rateLimit: 5, // max messages per rateDelta
        rateDelta: 1000, // time interval in ms (1 second)
        // highlight-end
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

export default ({ env }) => ({
  email: {
    config: {
      provider: 'nodemailer',
      providerOptions: {
        host: env('SMTP_HOST'),
        port: 465,
        secure: true,
        pool: true,
        // highlight-start
        rateLimit: 5,
        rateDelta: 1000,
        // highlight-end
        auth: {
          user: env('SMTP_USERNAME'),
          pass: env('SMTP_PASSWORD'),
        },
      },
      settings: {
        defaultFrom: 'hello@example.com',
        defaultReplyTo: 'hello@example.com',
      },
    },
  },
});

:::note Rate limiting requires connection pooling
rateLimit and rateDelta only take effect when pool: true is also set.
:::