# Categories and policies

> The eight categories (business, personal, disposable, relay, education, government, invalid, unknown) and how the b2b, strict and lenient policies map them.

Source: https://isbusinessemail.com/docs/categories-and-policies

Every check returns a **category** (what the address is) and a **recommendation** (what to do about it under a policy). Categories are facts about the domain; policies are your business rules.

## Categories

| Category | Meaning | Example |
|---|---|---|
| `business` | The company's own custom domain that receives mail | `jane@acme.io` |
| `personal` | A shared-domain provider: one domain, many unrelated people | `jane@gmail.com`, `jane@outlook.com`, ISP domains |
| `disposable` | Throwaway inbox, often valid for minutes | temporary-mail services |
| `relay` | Privacy relay forwarding to a hidden inbox | `…@privaterelay.appleid.com`, `…@duck.com`, `…@mozmail.com` |
| `education` | Schools and universities | `.edu`, `.ac.uk`, `.edu.au`, known university domains |
| `government` | Public sector | `.gov`, `.gov.uk`, `.gouv.fr`, `.gc.ca`, `.mil`, `europa.eu` |
| `invalid` | Can't receive mail: bad syntax, non-existent domain, no MX or a null MX | `jane@acme`, `jane@nonexistent-domain-123.com` |
| `unknown` | A custom domain with too little evidence to call (very new, parked, no SPF/DMARC, forwarding-only mail) | a 3-day-old domain with no website |

`is_business` is `true` for `business`, `education` and `government`.

### The core rule

**A business email is on the company's own custom domain. A personal email is on a shared domain.** We ask "is this domain shared or custom?", not "is this a big company?". A one-person consultancy on `jane-consulting.com` is `business`. A Fortune 500 employee using `@gmail.com` is `personal`.

Lists decide most cases. For everything else, DNS signals adjust `confidence`. Strong evidence of a shared or disposable domain (consumer-only mail servers, mail servers shared by disposable services) overrides the "custom domain" default.

### Precedence

When lists disagree, this order wins: admin override → blocked → disposable → relay → shared → education/government → custom. A more specific entry beats a parent domain, so `alumni.university.edu` can be `personal` while `university.edu` is `education`.

## Policies

Choose with `policy=b2b|strict|lenient`. The default is `b2b`.

| Input | `b2b` (default) | `strict` | `lenient` |
|---|---|---|---|
| `business` | allow | allow | allow |
| `education` | allow | allow | allow |
| `government` | allow | allow | allow |
| role account (`info@`, `sales@`…) on an allowed domain | review | **block** | allow |
| `unknown` | review | **block** | allow |
| `personal` | block | block | allow |
| `relay` | block | block | allow |
| `disposable` | block | block | block |
| `invalid` | block | block | block |
| blocked (`is_blocked: true`) | block | block | block |

Blocked isn't a category of its own. A blocklist match sets `is_blocked: true` with reason `blocked_domain` or `blocked_email`, and forces `block` under every policy. `category` still describes the domain.

### Which policy should I use?

- **`b2b`**: sales-led or PLG B2B products that want company signups but don't want to lose edge cases. `review` gives you a middle lane.
- **`strict`**: products that require a company tenant from day one (for example, an integration that needs Microsoft 365 admin consent), or free trials with real abuse costs.
- **`lenient`**: consumer-friendly or freemium products that only want to keep out throwaway and broken addresses.

### What to do with `review`

`review` means "probably fine, but look again". Common handling:

- Let the user in and flag the account in your admin.
- Require email verification before the trial starts.
- Shorten the trial or hold back expensive features until a human approves.
- Route to sales for a quick qualification.

## Policy vs your own rules

Policies are deliberately simple. If you need something else, for example "accept `relay` but only on paid plans", call with any policy and decide from `category` and the flags yourself. The [reason codes](https://isbusinessemail.com/docs/reason-codes) give you the full picture.