---
title: "Plus-Sign Aliasing and Catch-All Addresses"
description: "Tag test emails with plus-sign aliases, capture every address on a domain with a catch-all account, and track each account's storage quota."
canonical_url: "https://smtp.dev/docs/features/account/"
last_updated: "2026-08-16T22:38:03.931Z"
---

## Plus-Sign Aliasing

Any email sent to `user+anything@yourdomain.com` delivers to `user@yourdomain.com`. This works automatically, no configuration needed.

### Examples

```text
john@example.com               # The actual account
john+shopping@example.com      # Delivers to john@example.com
john+github@example.com        # Delivers to john@example.com
john+test-run-42@example.com   # Delivers to john@example.com
```

The part after `+` is ignored for delivery but preserved in the `To` header, so you can filter or search by it.

## Catch-All Addresses

A catch-all account captures every email sent to your domain that doesn't match an existing account.

### Setup

<steps level="4">

#### Go to the [Accounts](/accounts) page

#### Create a new account with `*` as the username

#### Select your domain and set a password

#### Any email to an address that doesn't have its own account will land here

</steps>

### How It Works

Say your domain is `example.com` and you have one regular account (`support@example.com`) plus a catch-all (`*@example.com`):

- `support@example.com` -> delivered to the **support** account (exact match wins)
- `sales@example.com` -> delivered to the **catch-all**
- `anything-at-all@example.com` -> delivered to the **catch-all**

## Storage Quota

Each account has a storage quota. The accounts list shows how much space is used. If an account fills up, incoming messages will be rejected until you delete old messages.