> ## Documentation Index
> Fetch the complete documentation index at: https://stytch.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Messaging overview

> Stytch provides reliable and timely email, SMS, and WhatsApp messaging through our providers out-of-the-box, allowing you to spend less time setting up and managing deliverability in your authentication services.

<Info>
  When designing your applications and login flows which utilize messaging APIs, be sure to consider Stytch's [rate limits](/resources/policies/platform/rate-limits).
</Info>

## Email

By default, Stytch's built-in email messaging comes from the following senders:

* `login@stytch.com` for Live environments
* `login@stytchtest.com` for Test environments

The Test environment sender does not support production use and should be used for testing purposes only.

You can also configure emails to be sent from your own sender and domain, and [customize email templates](/resources/branding/custom-email-templates).

## SMS and WhatsApp

SMS messages include your Project name in Live environments only.

SMS/WhatsApp messaging is only enabled for United States and Canada numbers by default. To enable additional countries, enable them in the [Country Code Allowlist](https://stytch.com/dashboard/country-code-allowlists).

We **strongly recommend** reading through our [toll fraud guide](/resources/policies/messaging/toll-fraud) before enabling international SMS/WhatsApp messaging.