← All tools
Email Verifier
Catch the addresses that will bounce before you send. Paste a list or upload a CSV and get every address scored from 0 to 100: syntax, whether the domain can really receive mail, disposable and role addresses, probable typos flagged, how old the domain is, whether it’s blocklisted - and, where the mail server cooperates, whether the mailbox itself exists.
Every address goes through six layers
1Syntax & placeholdersFormat and length, plus reserved domains like example.com that never receive mail.
2Domain & mail serversMX records, null MX, parked domains - and who hosts the mail (Google, Microsoft, a gateway).
3Disposable & roleThrowaway services and their look-alikes, info@ and test@, random-looking names.
4Typosgmial.com is flagged with what was probably meant. We never change your data.
5Deep checksDomain age from the registry; Spamhaus DBL, SURBL and URIBL listings.
6Mailbox confirmationThe mail server is asked whether the address exists, and told to stop before any message is sent.
Score 0-100 per address · CSV keeps all your columns · addresses are never stored, only an irreversible hash for a few hours.
What this does - and doesn’t - tell you
What’s checked
- Syntax and placeholders: one @, valid characters and length, and reserved domains like example.com that never receive mail.
- The domain: it exists, publishes MX records, those mail servers resolve to a real address, it isn’t a null MX or a parked domain, and who hosts the mail (Google Workspace, Microsoft 365, a security gateway…).
- Disposable addresses: a list of throwaway services plus detection of look-alike domains that use the same mail servers.
- Role, placeholder and random-looking names such as info@, test@ and xk2j9qpl@, and probable typos of popular domains (gmial.com, acme.con), flagged with the address that was probably meant. We never correct an address for you: a corrected address can belong to someone else.
- Deep checks: domain age from the registry, and Spamhaus DBL, SURBL and URIBL listings.
- Mailbox confirmation over SMTP, when shown as an option: the mail server is asked whether the address exists, and told to stop before any message is sent.
- Lists: upload a CSV and keep every column - the downloads give your own file back with the verdict added. Duplicates are found even when Gmail dots and +tags differ. B2B mode counts free mailboxes (gmail, yahoo) against an address; role addresses can be allowed.
Worth knowing
- No verifier can confirm every mailbox. Yahoo, AOL and many company mail gateways say yes to every address, so those come back as “accept-all” rather than valid. Microsoft blocks most cloud servers, so Outlook.com and Hotmail mailboxes can’t be confirmed. Some servers delay a first-time sender (greylisting): we retry those automatically (after 2, 4 and 8 minutes, while the page stays open), so there is nothing to click, and a button lets you re-check whatever is still unsettled.
- Mailbox confirmation never sends an email: the conversation ends before any message data, with an empty sender, so nothing is delivered and no domain’s reputation is involved.
- “Valid” means worth sending to. Only a result marked confirmed means the mail server itself agreed the mailbox exists.
- The disposable list covers the well-known throwaway services and their servers, not every one - new ones appear daily.
- Your addresses aren’t stored. To avoid asking a mail server about the same address twice, each checked address is kept for a few hours only as an irreversible hash - never the address itself. Your last result is saved in your own browser, not on our server. A clean list isn’t enough on its own: check the sending domain with the Domain Health Check.
A bounce rate above about 2% damages the domain you send from. We build and run cold email infrastructure that stays under it.
How we help: Consulting · Private infrastructure · Managed mailboxes · Monthly support