Custom email provider and templates: SMTP setup, verification emails, liquid

TL;DR: Auth0's built-in email provider is for testing. Production needs your own provider before the first real user, plus templates that users actually recognize. Configure the provider Dashboard > Branding > Email Provider. Verify the domain (SPF/DKIM) at your DNS; without it, verification and reset emails land in spam and your login funnel silently leaks.

The fix

Custom email provider

1. Configure the provider

Dashboard > Branding > Email Provider. Options: SendGrid, SES, Mailgun, Mandrill, SparkPost, or custom SMTP. Fill in credentials and the from address. Verify the domain (SPF/DKIM) at your DNS; without it, verification and reset emails land in spam and your login funnel silently leaks.

2. Templates

Branding > Email Templates: verification email, welcome, password reset, blocked account, MFA enrollment. Each supports Liquid syntax for variables (user.email, application.name). Customize:

• From name users recognize (your product, not "Auth0").
• Subject lines that survive spam filters (no ALL CAPS, no excessive links).
• The blocked-account template MUST be clear: it is the self-serve unblock path.

3. Test

Send test emails from the dashboard. Then do a real signup in incognito and time the verification email arrival. Over a minute consistently means provider or DNS issues.

4. Monitor

Watch the provider's bounce/suppression lists. One hard bounce suppresses that address; users then report "never got the email" and resends do nothing until the suppression is cleared.

Checklist

• Custom provider + verified domain before launch.
• Every template a user can receive has been read by a human on your team.

When to use this

• This covers exactly what the title says: Custom email provider and templates.
• You are setting this up for the first time, or auditing an existing setup.
• You want the key gotchas in one place before you start.

When not to use this

• You are doing a different workflow with Custom; these steps are specific to the title above.
• You need the full reference docs; this is the short path, not the manual.

Compatibility

• Not pinned to a specific version; follows current Custom behavior.

Auth0's email customization docs describe the built-in provider limits, custom provider setup (SendGrid/SES/Mailgun/SMTP), and the Liquid-templated emails. Verified against live docs 2026-09-26.