# Email Verifier: Syntax, MX & Disposable-Domain Score (`catalyst_prime/email-verifier`) Actor

Validates email addresses without ever sending mail: syntax, live MX record, disposable-domain and role-account checks, rolled into a transparent 0-100 confidence score with a per-check breakdown. Never claims a mailbox was confirmed to exist.

- **URL**: https://apify.com/catalyst\_prime/email-verifier.md
- **Developed by:** [Catalyst](https://apify.com/catalyst_prime) (community)
- **Categories:** Lead generation, Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

Pay per usage

This Actor is paid per platform usage. The Actor is free to use, and you only pay for the Apify platform usage, which gets cheaper the higher subscription plan you have.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-usage

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Email Verifier: Syntax, MX and Disposable-Domain Confidence Score

Validates email addresses without ever sending mail: syntax, live MX record, disposable-domain
and role-account checks, rolled into a transparent 0-100 confidence score with a per-check
breakdown.

### What this checks, and what it does not

This is a **validate-without-sending** tool. It never opens a connection to any mail server and
never attempts to deliver anything. Concretely, it runs four checks per address:

1. **Syntax** — does the address have a valid shape (RFC 5322 practical subset)?
2. **MX record** — does the domain currently have a live, working mail server, confirmed by a
   real DNS lookup at run time (not a cached or guessed answer)?
3. **Disposable domain** — is the domain a known throwaway/temporary-email provider, checked
   against a bundled list of 75,000+ domains?
4. **Role account** — does the local part (before the `@`) look like a team inbox (`info@`,
   `support@`, `noreply@`, etc.) rather than one person's mailbox?

**What it cannot and does not claim: whether that specific mailbox actually exists.** Confirming
a mailbox requires an SMTP handshake with the destination mail server (an `RCPT TO` probe), which
this Actor deliberately does not do. No field in this Actor's output should ever be read as "we
confirmed this inbox is real." `mxFound: true` means the domain is set up to receive mail in
general, nothing more specific than that.

#### Why not go further and check the mailbox too

Most competing "email verifier" Actors advertise SMTP/mailbox verification. We tested it
directly: outbound port 25 (the port SMTP mail delivery uses) is blocked at the platform level,
against four independent mail providers (Gmail, Outlook, Yahoo, Fastmail). Every connection
attempt times out identically, with no response from the destination at all. Rather than claim
something that can't actually be verified this way, this Actor is honest about the boundary:
syntax, MX, disposable-domain and role-account are the four things that are genuinely checkable,
and that is exactly what it reports, nothing more.

### Input

Give it one or more email addresses via `emails` (a JSON array, a single string, or a
comma/newline separated list). `emailAddresses` works the same way, as an alias.

| Field | Type | Default | Description |
|---|---|---|---|
| `emails` | array of strings | none | Email addresses to check. Supply this or the alias below. |
| `emailAddresses` | array | none | Alias of `emails`. |
| `timeoutSeconds` | integer | `15` | Per-address DNS lookup timeout, clamped to 3-60. |

### Output

One dataset item per input email address:

```json
{
  "email": "person@example.com",
  "syntaxValid": true,
  "mxFound": true,
  "mxHosts": ["aspmx.l.google.com", "alt1.aspmx.l.google.com"],
  "isDisposableDomain": false,
  "isRoleAccount": false,
  "confidenceScore": 100,
  "checksRun": ["syntax", "mx", "disposable", "role"],
  "charged": false
}
```

Real, unmodified output from a local run against a small mixed batch:

```json
{"email":"not-an-email","syntaxValid":false,"mxFound":false,"mxHosts":[],"isDisposableDomain":false,"isRoleAccount":false,"confidenceScore":0,"checksRun":["syntax"],"charged":false}
{"email":"info@microsoft.com","syntaxValid":true,"mxFound":true,"mxHosts":["microsoft-com.mail.protection.outlook.com"],"isDisposableDomain":false,"isRoleAccount":true,"confidenceScore":90,"checksRun":["syntax","mx","disposable","role"],"charged":false}
{"email":"someone@mailinator.com","syntaxValid":true,"mxFound":true,"mxHosts":["mail2.mailinator.com","mail.mailinator.com"],"isDisposableDomain":true,"isRoleAccount":false,"confidenceScore":80,"checksRun":["syntax","mx","disposable","role"],"charged":false}
{"email":"user@example.com","syntaxValid":true,"mxFound":false,"mxHosts":[],"isDisposableDomain":false,"isRoleAccount":false,"confidenceScore":60,"checksRun":["syntax","mx","disposable","role"],"charged":false}
```

The last row, `user@example.com`, resolves against a domain with a DNS "null MX" record, the
domain's own explicit declaration that it accepts no mail at all. That is a confirmed, real
answer (`mxFound: false`), not a lookup failure.

**`error`** is set only when the DNS lookup itself fails for reasons unrelated to the domain (a
transient resolver problem). It stays empty on a syntax-invalid row: that is a complete answer,
not a failure.

### Scoring

`confidenceScore` is additive out of 100: syntax (30) + live MX (40) + not disposable (20) + not a
role account (10). Invalid syntax scores 0 outright. This is deliberately a graded score with a
visible `checksRun` breakdown, not a flat pass/fail boolean: a syntax-only row and a row that
passed all four checks both show exactly what was and wasn't checked.

### Pricing

**Free.** This Actor has no price set, so a run costs you only your own Apify platform usage.

The code supports pay-per-event billing on a single `email-verify` event, priced per processed
address, if a price is ever set on the Apify Console. A row is only ever charged when it carries a
complete answer: a confirmed syntax-invalid address counts (you were told exactly why it's
invalid), a genuine DNS lookup failure does not. Nothing is hardcoded: the Actor reads its own
current price from the platform at startup and runs unmetered when there isn't one.

### Third-party data bundled in this Actor

The disposable-domain list is `disposable/disposable-email-domains`
(github.com/disposable/disposable-email-domains), MIT licensed, pinned to commit
`7011bb4c072d96fbaed9ef96657ec6f873185d9c` (2026-09-26), 75,390 domains. Vendored into this
Actor's image at build time (`data/disposable_domains.txt`), never fetched at runtime.

### Before publishing this Actor

- \[x] `processItem` implements syntax, MX, disposable-domain and role-account checks; `Result` in
  `types.go` matches.
- \[x] `.actor/dataset_schema.json` documents the real output fields, read directly from `Result`.
- \[x] This README's Input/Output sections match the real code.
- \[x] Charge guard holds: `pricing.Charge` is only called on a branch with a complete, returnable
  answer (a confirmed valid/invalid syntax result, or a completed MX lookup), never on a
  genuine lookup failure.
- \[ ] `verify_gate.py` run against a real Apify platform dataset, PASS.
- \[x] No scraping, no login, no target site at all: nothing to violate any site's terms.
- \[ ] Measured memory, seconds, compute units and cost per run on a real platform run.

# Actor input Schema

## `emails` (type: `array`):

List of email addresses to check. Accepts a JSON array, a single string, or a comma/newline separated list.

## `emailAddresses` (type: `array`):

Alias of 'emails' for compatibility with tools that use this field name.

## `timeoutSeconds` (type: `integer`):

How long to wait for each item before giving up. Clamped to 3-60.

## Actor input object example

```json
{
  "emails": [
    "person@example.com"
  ],
  "timeoutSeconds": 15
}
```

# Actor output Schema

## `results` (type: `string`):

The full set of results, one item per input entry.

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "emails": [
        "person@example.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("catalyst_prime/email-verifier").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "emails": ["person@example.com"] }

# Run the Actor and wait for it to finish
run = client.actor("catalyst_prime/email-verifier").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "emails": [
    "person@example.com"
  ]
}' |
apify call catalyst_prime/email-verifier --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,catalyst_prime/email-verifier"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/LUM1PGOF4VdMf4kBj/builds/kePCdxqCX4fehGUGk/openapi.json