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Free tool — no sign-up required

Email Validator

Free bulk email verifier and list cleaning tool. Validate single addresses or upload CSV files to find invalid emails, detect ~210k+ disposable domains, and verify live DNS MX records.

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Comprehensive email health diagnostics.

Evaluate technical mail server compliance, disposable domains, and deliverability heuristics before sending campaigns to real customers.

RFC 5322 Syntax & Format

Verifies standard local-part and domain grammar, invalid characters, missing TLDs, and plus-address tags.

210k+ Disposable Domains

Instantly detects temporary and throwaway inboxes (Mailinator, Yopmail, Temp-Mail, Guerrilla Mail) with zero lag.

Live DNS MX Mail Servers

Queries public DNS for active mail exchange records, detects unreachable domains and implicit MX fallbacks.

Role & Provider Detection

Differentiates personal mailboxes from shared team aliases (support@, sales@, admin@) and consumer providers.

Automate email verification via API.

Integrate automated email validation into your signup flows, onboarding forms, or batch list imports.

1

Install the Node.js package

npm install reloop-email
2

Verify email health with Node.js

verify_email.ts
1import { Reloop } from "reloop-email";
2

3const client = new Reloop({
4  apiKey: process.env.RELOOP_API_KEY,
5});
6

7// 1. Verify a single email address
8const result = await client.tools.email.verify("alex@reloop.sh");
9

10console.log(result.health.state);   // "undeliverable"
11console.log(result.health.score);   // 0
12console.log(result.health.reason);  // "no_mx_records"
13console.log(result.mailServer.implicitMxRecord); // true
14

15// 2. Or submit an asynchronous batch CSV/list check
16const batch = await client.tools.email.verifyBatch({
17  emails: ["user1@gmail.com", "user2@mailinator.com"],
18});
19console.log(`Batch token: ${batch.token}`);
3

Inspect JSON email health report (200 OK)

response.json
1{
2  "input": "alex@reloop.sh",
3  "domain": "reloop.sh",
4  "verdict": "invalid",
5  "isValidSyntax": true,
6  "isDisposable": false,
7  "isRoleAddress": false,
8  "isFreeProvider": false,
9  "mxRecords": [],
10  "confidence": 0.7,
11  "riskScore": 0.38,
12  "flags": ["NO_MX_RECORDS"],
13  "health": {
14    "status": "fail",
15    "summary": "Domain does not accept mail (no active MX records).",
16    "state": "undeliverable",
17    "score": 0,
18    "reason": "no_mx_records",
19    "user": "alex",
20    "domain": "reloop.sh",
21    "tag": null,
22    "attributes": {
23      "free": false,
24      "role": false,
25      "disposable": false,
26      "acceptAll": false,
27      "tag": false,
28      "numericalCharacters": 0,
29      "alphabeticalCharacters": 4,
30      "unicodeSymbols": 0,
31      "mailboxFull": false,
32      "noReply": false,
33      "secureEmailGateway": false
34    },
35    "mailServer": {
36      "smtpProvider": null,
37      "mxRecord": "reloop.sh",
38      "mxRecords": [],
39      "implicitMxRecord": true,
40      "hasMx": false
41    }
42  }
43}

Frequently asked questions.

Everything you need to know about email health scoring, batch limits, privacy, and deliverability.

Ship your first email in minutes

Open-source, deliverability-focused, and yours to self-host or run on Reloop Cloud. No lock-in, no rewrite later.

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