For the complete site index, see llms.txt. Docs index: llms-docs.txt. Marketing corpus: llms-full.txt. Docs corpus: llms-full-docs.txt. Prefer markdown URLs where available (append .md).. Product skill: skill.md. Pricing: pricing.md. Docs MCP: /docs/mcp. Site MCP: /mcp.

Free tool — no sign-up required

Free Email Validator

Free email validator and bulk list cleaner. Check a single address or upload a CSV to find invalid emails, detect ~210k+ disposable domains, and verify live DNS MX records — no signup required.

Try:

How this free email validator works.

Three steps from raw addresses to a cleaner list — syntax, disposable domains, and live MX checks without intrusive SMTP probes.

01

Paste an email or upload a CSV

Check one address instantly, or upload a CSV/TXT list (up to 1,000 rows in the browser). We auto-detect the email column and remove duplicates before scoring.

02

Run syntax, disposable, and MX checks

Each address is validated against RFC 5322 grammar, a ~210,000-domain disposable catalogue, role/free-provider signals, and live DNS MX records — without SMTP mailbox probing.

03

Get a health score and clean export

See deliverability state, risk flags, and mail-server details per address. Download a cleaned list for campaigns, or automate the same checks with the validation API.

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.

To clean an email list, upload your CSV or TXT file into the Bulk Email Verifier tab. The tool automatically detects your email column, deduplicates entries, and validates each address against RFC 5322 syntax, ~210,000 disposable domains, and live DNS MX records. You can then download a sanitized CSV containing only 100% deliverable emails.

Yes. The web interface directly processes lists up to 1,000 emails per batch. For larger lists of 5,000 to 100,000+ addresses, you can split your CSV or use our high-throughput batch API endpoint (POST /api/tools/v1/email-health-check/batch) which evaluates large datasets asynchronously with in-memory domain caching.

The tool checks incoming email domains against an active database of over 210,000 temporary and disposable email providers—including Mailinator, Yopmail, Temp-Mail, 10MinuteMail, and Guerrilla Mail. Throwaway inboxes are flagged with a 0 deliverability score to prevent spam signups.

An address can have correct syntax (like user@dead-domain.com) but still be undeliverable if the domain does not have active MX mail exchange records answering in DNS or if the domain is listed as a disposable throwaway provider. Messages sent to domains without MX servers will immediately hard bounce.

Cleaning your email list removes invalid addresses, typos, dead domains, and spam traps before you send campaigns. Maintaining a bounce rate under 1% ensures major inbox providers (Google, Microsoft, Yahoo) route your marketing and transactional messages to the Primary inbox rather than the spam folder.

Duplicates are automatically identified and consolidated case-insensitively. The tool evaluates only unique addresses to maximize speed and displays a notification banner showing the exact count of duplicates removed from your list.

No. It does not send test messages or initiate intrusive SMTP socket handshakes (RCPT TO) that could trigger greylisting, rate limits, or spam trap flags. All checks use secure DNS queries, algorithmic parsing, and in-memory catalogue matching.

Yes. You can use our REST API endpoints: POST /api/tools/v1/email-health-check for single-address verification and POST /api/tools/v1/email-health-check/batch for bulk list cleaning. Official SDKs are available for Node.js, Python, Go, PHP, Ruby, Java, .NET, Rust, and cURL.

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.

Get started freeDocumentation
Reloop