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SMTP guides

Auth0

Send Auth0 emails through usend with the custom SMTP provider.

Auth0 can send verification, welcome and password-change emails through your own SMTP server. Reference: Send with SMTP.

Before you start

  1. Verify your domain in usend.
  2. Create a sending_access API key for it.

Configure

In the Auth0 Dashboard go to Branding → Email Provider, turn on Use my own email provider and pick SMTP (the generic option):

FieldValue
FromAn address on your verified domain, for example Acme <[email protected]>
Hostsmtp.usend.et
Port587
Usernameusend
PasswordYour usend API key

Save, then use Send Test Email. Auth0 sends a test message to the address of the dashboard user.

With the Management API

Shell
curl -X POST "https://YOUR_TENANT.auth0.com/api/v2/emails/provider" \
  -H "Authorization: Bearer $AUTH0_MGMT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "smtp",
    "enabled": true,
    "default_from_address": "Acme <[email protected]>",
    "credentials": {
      "smtp_host": "smtp.usend.et",
      "smtp_port": 587,
      "smtp_user": "usend",
      "smtp_pass": "us_123456789"
    }
  }'

Tips

  • The From address must be on a verified domain. If Auth0 shows an error mentioning 554, the address or the organization's status is the cause: see the SMTP errors.
  • Auth0 mail is transactional. Keep tracking off for the verification and reset links.
  • Customize the email templates under Branding → Email Templates; the From and subject can be set per template.
  • While the usend organization is in the sandbox, only verified members receive mail.
  • Rotate the key if you ever paste it somewhere it should not be: Handling leaked API keys.