Auth0 Emails Sent With Non-Custom Domains Despite Enabling Custom Domains

Auth0 sends emails using non-custom domains when the tenant lacks a default custom domain configuration. Setting the desired custom domain as the default resolves the issue and ensures Auth0 uses the correct domain for notifications. Administrators observe that Auth0 sends emails from non-custom domains even after enabling the Enable custom domains for email and phone notifications setting, and that clicking the non-custom URLs results in errors.

• Auth0
• Custom Domains
• Email Notifications
• Phone Notifications

Auth0 introduced the default custom domain feature with the release of support for multiple custom domains. Auth0 requires administrators to set a default custom domain for the tenant explicitly. Auth0 will deprecate the enable_custom_domain_in_emails flag in the future and rely exclusively on the default custom domain for email and phone notifications.

How is the default custom domain configured for notifications?

Navigate to the custom domains settings in the branding menu to designate the specific custom domain as the tenant's default and enable the custom domains toggle.

1. Navigate to Branding, and then select Custom Domains.
2. Set the desired custom domain as the tenant's default custom domain.
3. Enable the Enable custom domains for email and phone notifications toggle.