No. 03 · Email validator

Email validator

Check a whole list at once: syntax and length rules, likely typos like gmial.com, role accounts, disposable domains and, if you want, MX records. Results export to CSV.

Or drop a .txt or .csv file

Options

Looks up each domain's mail servers with Cloudflare's DNS-over-HTTPS service. Only domain names are sent, once each, at most four at a time.

This checks format, typos and DNS. It cannot prove a mailbox exists: only the receiving server knows, and many accept everything and bounce later.

Results

How to use the email validator

Paste addresses one per line (commas, semicolons and Name <address> entries work too) or drop a .txt/.csv file, then click Validate. Each address is marked Valid, Risky or Invalid with the reasons spelled out. Filter the table, apply typo fixes, then copy the clean list or download the results as CSV.

What is checked

  • Syntax: one @, allowed characters, no leading, trailing or double dots, 64 characters before the @, 253 for the domain, 254 overall, valid domain labels and a real-looking top-level domain (checked against the IANA list). Internationalised domains are converted to punycode.
  • Typos: domains a keystroke or two away from popular providers (gmial.com, hotmial.com, yaho.com, outlok.com, gmail.con) get a suggested fix, found with edit distance.
  • Role accounts: shared inboxes such as admin@, info@, support@ and no-reply@. They are valid, but often unwatched or shared by a team.
  • Disposable domains: addresses at well-known throwaway services, from a bundled list of a few hundred domains. It is not exhaustive.
  • MX records (optional): whether the domain publishes mail servers, falls back to its A/AAAA record, explicitly refuses mail (null MX), or does not exist at all.

On the other side of the fence? If you need a throwaway address yourself, for example to test your own sign-up form, CleanTempMail gives you a free temporary inbox with no sign-up.

The MX check here only reads mail-server records. To see a domain's full DNS record set, use the DNS lookup on WebTraceCheck.

Questions

Can this tell me whether a mailbox exists?

No, and no website can do that reliably. Only the receiving mail server knows, and many servers accept every address and bounce later. This tool tells you whether an address is well formed, likely mistyped, disposable or at a domain that cannot receive mail.

What does risky mean?

The address is technically valid but something deserves a look: a probable typo, a disposable domain, a top-level domain that is not on the IANA list, unusual syntax such as quoted names or IP addresses, or a domain without MX records.

Is my list sent anywhere?

Addresses never leave your browser. If you turn on the MX check, only the domain names are looked up with Cloudflare's public DNS-over-HTTPS service, once per domain.

How complete is the disposable-domain list?

It is a curated list of a few hundred well-known throwaway services and their alternate domains. New ones appear every day, so it catches the common cases but is not exhaustive.