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Email validator

Check an address against RFC 5322 syntax, length limits, domain structure and a live MX-record lookup — or paste a whole list and get typo suggestions, disposable and role-account flags and a CSV you can hand back to your ESP.

Free & unlimited
Mode
Email address
Validation runs in your browser. MX record checks query Cloudflare DNS over HTTPS.

Two checkers on one page. The first takes a single address and walks it through seven named tests — allowed characters, a single well-formed @, domain structure, RFC 5322 syntax, the 64/255-character length limits, a disposable-provider check, and a live MX-record lookup — and scores it. The second takes up to 500 addresses pasted or loaded from a file, flags typos ("gnail.com"), role accounts (info@, sales@) and disposable domains, gives each a confidence figure, and exports the lot as CSV.

Key facts about Email validator

Key facts about Email validator
Checks run per addressCharacters, @ structure, domain structure, RFC 5322 syntax, length limits (local ≤ 64, domain ≤ 255), disposable provider, MX record
MX lookupSingle-address mode only: a live DNS-over-HTTPS query that returns the domain's actual mail hosts
MX in list modeNot a live query. The list checker marks the well-known providers as verified and every other domain as unknown — run those through the single-address mode
Bulk capacity500 addresses per batch, one per line or comma/semicolon separated
Typo detectionSuggests the intended domain for near-misses of the common providers — gnail.com, hotmial.com, yaho.com and similar
Role-account flagMarks info@, sales@, support@, admin@ and friends, which bounce hardest on cold lists
ExportCSV with address, valid, syntax, MX, disposable, role-based, confidence, issues and suggestion columns
What it cannot tell youWhether the mailbox exists. Nothing short of sending mail can, and SMTP probing is what gets senders blocklisted

What happens to your file

The syntax, length, typo, role-account and disposable checks all run in this browser tab — the address itself is never sent anywhere for those, and the list mode makes no network request at all. The single-address MX check is the one exception, and it is a real request: the page asks Cloudflare's public DNS-over-HTTPS resolver (cloudflare-dns.com) for the MX records of the DOMAIN part only. The local part — everything before the @ — is never included in that query, and no address, list or result is stored by this site.

About this tool

  1. 1

    Enter one address

    The default mode runs all seven checks and gives each a pass, a warning or a fail with the reason.

  2. 2

    Read the MX line

    It names the mail hosts the domain actually publishes. No MX records means the domain cannot receive mail at all.

  3. 3

    Switch to List & CSV export for a batch

    Paste up to 500 addresses, or load them from a text or CSV file.

  4. 4

    Review the flags

    Typo suggestions, disposable providers and role accounts are marked separately from hard syntax failures.

  5. 5

    Export

    Download the results as CSV to feed back into your ESP or CRM.

Specs & compatibility
ModesSyntax & MX check · List & CSV export
Standard appliedRFC 5322 addr-spec, with the RFC 5321 length limits
Network callsOne per domain in single-address mode, to cloudflare-dns.com, for MX records only. The list mode makes none
Batch limit500 addresses per run
Import / exportPaste, or load a .txt/.csv; export CSV
Browser supportAny modern browser; the MX check needs a working internet connection
  • Valid syntax plus valid MX is the strongest signal you can get without sending mail — treat anything more confident as a sales claim.
  • Run a list through this before an import, not after a bounce report: most ESPs charge you for the bounce.
  • Role accounts are not invalid, they are just bad targets for cold email and often route to a shared inbox.
  • A disposable-domain flag is a signup-quality signal, not a syntax failure; decide per product whether to block them.
  • Plus-addressing (you+tag@gmail.com) is legal and deliverable — do not strip it from a list.
  • Seven named checks per address, each with a reason
  • Live MX-record lookup for the domain (single-address mode)
  • Typo suggestions for common provider misspellings
  • Disposable and role-account detection
  • Bulk validation of up to 500 addresses
  • CSV import and CSV export
  • Syntax checks run entirely in the browser
  • Clean a mailing list before importing it and paying for the bounces.
  • Validate a signup form's submissions and catch "gnail.com" before the welcome mail fails.
  • Spot disposable addresses in a free-trial funnel.
  • Audit a CRM export for domains that no longer have mail servers.
  • Check one address a colleague dictated over the phone.
No. It means the address is well-formed and its domain publishes mail servers. Whether that specific mailbox exists, is full, or is accepting mail from you can only be learned by sending — and probing it over SMTP is a fast way onto a blocklist.
The address itself, no. The syntax, length, typo, role and disposable checks all run in this tab, and the list mode makes no request at all. The single-address MX check sends only the domain — the part after the @ — to Cloudflare's public DNS resolver, which is what any mail server would do anyway.
The share of checks that passed, weighted so hard failures (bad syntax, no MX) dominate and soft flags (role account, disposable) only reduce it. It is a triage aid, not a deliverability guarantee.
500 per batch in the List & CSV export mode. Paste them one per line, or separated by commas or semicolons, or load a .txt or .csv file.
Because it is valid — Mailinator and Guerrilla Mail addresses receive mail. The flag exists so you can decide whether a temporary inbox is acceptable for your signup flow, not because the address is malformed.
Into the List & CSV export mode here. Two pages with the same name were competing for the same query; the list checker's typo suggestions, role-account flags and CSV export all moved across intact.

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