# Supabase (SMTP)

> Send Supabase Auth emails through MailBlastr by configuring custom SMTP.

Supabase Auth sends confirmation, magic-link, and password-reset emails through its built-in SMTP server, which is rate-limited and only meant for testing. Wire it up to MailBlastr's SMTP relay so auth emails are delivered reliably and tracked in your dashboard.

## Prerequisites

- A MailBlastr [API key](https://www.mailblastr.com/docs/api-keys/overview).
- A [verified domain](https://www.mailblastr.com/docs/domains/managing) to send from.

## 1. Get your SMTP credentials

You'll configure Supabase with the following MailBlastr credentials:

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `Host` | string | No | `smtp.mailblastr.com` |
| `Port` | number | No | `465` (implicit TLS) or `587` (STARTTLS). |
| `Username` | string | No | `mailblastr` |
| `Password` | string | No | Your API key, e.g. `mb_xxxxxxxxx`. |

## 2. Enable custom SMTP in Supabase

After logging into Supabase, enable the SMTP integration:

1. **Open your project** — Go to your Supabase project.
2. **Authentication** — Click **Authentication** in the left sidebar.
3. **Email notifications** — Click **Email** under the **Notifications** section.
4. **SMTP Settings** — Click **SMTP Settings** and enable custom SMTP.
5. **Sender details** — Add your Sender email and name (both required). The Sender email must be on a verified domain, e.g. `support@yourdomain.com` and `Acme Support`.
6. **Paste credentials** — Enter the MailBlastr host, port, username (`mailblastr`), and password (your API key) from the section above.

Click **Save**. From now on, all Supabase Auth emails are sent through MailBlastr.

> **Warning:** The Sender email must be on a domain you have verified in MailBlastr, otherwise Supabase's sends will be rejected.