Configure Mailgun as External SMTP Email Provider
Auth0 allows you to configure your own SMTP email provider so you can more completely manage, monitor, and troubleshoot your email communications. Auth0's built-in email infrastructure should be used for testing emails only.
Prerequisites
To ensure that emails can be sent from Auth0 to your SMTP, open ports and allow inbound connections from specific IP addresses. To update the list of IPs, navigate to Dashboard > Branding > Email Provider. See Add IP Addresses to AllowList for details.
You must have a Mailgun account.
Configure Mailgun
Log in to your Mailgun.
Navigate to Mailgun Sending > Domains, and add your custom domain. Mailgun allows sending emails from only verified domains.
Navigate to Mailgun Settings > API Keys. Your API key was created when you signed up for your account; copy it from Private API Key.
Navigate to Auth0 Dashboard > Branding > Email Provider.
Activate the Use my own email provider toggle.
Click the Mailgun logo.
Provide a From email address, enter the Domain you previously added to Mailgun, enter the Mailgun API Key you previously copied, select your Region.
Click Save.
Test email
You can now send a test email using the Send Test Email button. If you have configured everything correctly, you will receive a confirmation email. If you do not receive an email after a few minutes, please check your Auth0 logs for any failures.
The Mailgun Dashboard will now display delivery insights for all emails that have been sent to your users.