SMTP Email Provider Overview

Configure an external SMTP email provider to send emails in production and to use email templates to customize their appearance and content.

Auth0’s email-based workflows handle when emails are sent and what the emails contain. To deliver the outgoing mail, you need an SMTP server or service from an external email provider.

You can configure a single email provider to handle all emails sent from your tenant. We offer three options for this configuration: integration with third-party email providers we support, direct SMTP server connections, or custom configuration with Actions.

Supported Email Provider Integrations

Our email provider integrations let you configure your tenant by adding API credentials from a supported third-party provider.

We support the following providers:

• Amazon SES
• Azure Communication Services
• Mandrill
• Microsoft 365 Exchange Online
• SendGrid
• SparkPost
• Mailgun

Custom Configuration with Actions

You can write an Action to connect to any external email provider. This lets you implement custom logic for your use case and have more control over the email delivery process.

For more information, read Custom Email Provider Configuration with Actions.

SMTP Server Configuration

You can configure your tenant by adding SMTP server details directly. This is a good option if:

• We don’t support integration with your chosen email provider and you don’t need or want to write an Action for configuration.

• You want to set up a dummy SMTP server (like Debug Mail, FakeSMTP, or smtp4dev) for testing.

We don’t allow certain false domains commonly used during testing. Use real email addresses to avoid disruption or errors.

For instructions, read Configure an Email Provider with SMTP Server Details.

The Built-In Email Provider

The built-in email provider is available by default and requires no configuration. However, it does not support production use and has the following limits:

• You cannot use custom email templates.

• You cannot customize the From Address. All emails are sent from [e-mail].

• You are limited to sending 10 emails per minute, regardless of email type.

• If your emails have a high bounce rate, we may reduce or temporarily block the ability to send email from your tenant.

To remove these limits and use emails in production, set up an external SMTP email provider.