Troubleshoot Custom Email Provider Delivery Issues

Auth0 allows you to configure your own SMTP email providers to manage, monitor, and troubleshoot your email communications. If you experience email delivery issues, there are several settings to review before contacting Auth0 support.

You must use a custom email provider. The built-in email provider is for testing only and should not be a substitute for long term email management.

Review your infrastructure and domain configuration

Configure your email provider with the following authentication standards:

  • DomainKeys Identified Mail (DKIM)

  • Sender Policy Framework (SPF)

  • Domain-based Message Authentication, Reporting, and Conformance (DMARC)

You can use several tools to review the settings of DNS records relating to DKIM, SPF, and DMARC. Built-in command line tools like dig and nslookup can help you diagnose your MX records and other common routing issues.

Online tools like MXToolBox and DNSChecker can also analyze settings related to authentication standards and are helpful in identifying misconfigurations or changes needed in your email settings.

Microsoft Exchange specific issues

If you use Microsoft Exchange as your email provider, your emails may be quarantined if Exchange deems them as high-risk. This can happen when emails route from an outside source.

If Microsoft Exchange quarantines messages, an administrator can view the messages in a special inbox and determine if there is a DMARC alignment failure, causing the messages to appear as spam.

SendGrid specific issues

If you use SendGrid as your email provider, your emails may be suppressed if the recipient's email server rejects the message. To learn more, read Different Types of Suppression in SendGrid Docs.

In certain cases, SendGrid will “Drop” a message to a specific email address in order to protect your sender reputation. To learn more about "Drops" and how to remove them, read Drops on SendGrid Docs.

If you are using passwordless authentication with email, ensure that the From email address value for your passwordless connection matches the From email address value you're using for SendGrid.

Contacting Auth0 Support

If you review your custom email provider settings and ensure your domain implements DKIM, SPF, and DMARC protocols and your email delivery is still failing, you may need to contact the Auth0 support team for review.

Our support team can verify if your email provider receives messages and the error returned if they are not accepted. To learn more, read Open and Manage Support Tickets.

Diagnose email delivery issues

If you have configured a custom provider but are not receiving notifications that emails are being sent, verify your provider configuration details in Auth0 and confirm your custom provider is available. To view log data regarding email notification errors, go to Dashboard > Monitoring > Logs and filter results on the Failed Sending Notification event type.

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