---
title: "Test auth provider emails: Supabase, Clerk, Auth0, Firebase"
description: "How to test the sign-up, login code, magic-link and password-reset emails your auth provider sends, and the sending limits that stop them arriving."
url: https://proxymail.qa/auth
---

Auth providers

# The emails your auth provider sends, tested end to end.

Supabase, Clerk, Auth0, Firebase, Auth.js and Better Auth all email your users: a code or link to verify, sign in or reset a password. Each has its own sending rules, and the default ones are often limited to a few emails or a few addresses. These guides cover what each provider sends, what stops it arriving, and how to test every email by hand or from your tests.

- [Supabase AuthConfirmation, magic-link, code and reset emails, and why the default sender won't email your test addresses.Read the guide →](https://proxymail.qa/auth/supabase)
- [ClerkVerification codes, email links and resets, when test-mode addresses aren't enough, and the development email cap.Read the guide →](https://proxymail.qa/auth/clerk)
- [Auth0Verification links, passwordless codes and resets, and the built-in email provider's limits.Read the guide →](https://proxymail.qa/auth/auth0)
- [Firebase AuthenticationVerification, reset and email-link sign-in emails on the web, and the daily sending limits.Read the guide →](https://proxymail.qa/auth/firebase)
- [Auth.js (NextAuth)Magic-link sign-in through your own email provider, its expiry, and what stops the email arriving.Read the guide →](https://proxymail.qa/auth/authjs)
- [Better AuthVerification, reset, magic-link and email OTP emails through your own provider, and their short expiry.Read the guide →](https://proxymail.qa/auth/better-auth)

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