Free emailvalidator.
Check up to 100 email addresses at once: the format, the domain's mail servers, throwaway and role addresses, and how likely the domain accepts every address.
How it works
- Paste addressesUp to 100 at a time
- See each resultLooks valid, risky or invalid, with why
- Download the listAs a CSV
Free, no sign-up. Checked live from our server. Nothing is stored.
The tool
Check email addresses
Up to 100 at a time, one per line or separated by commas.
What the results mean.
What the result means, and how to fix what it finds.
Invalid: remove them
An address is invalid when it isn't a real address format, when its domain has no mail server, or when it's from a throwaway service. Email to these bounces or goes nowhere. Bounces are one of the fastest ways to damage a sending domain, so remove invalid addresses before every campaign.
Risky: decide case by case
Role addresses like info@ or sales@ go to shared inboxes, get fewer replies and more complaints. Personal Gmail or Yahoo addresses are fine for some offers and wrong for business ones. Catch-all domains accept every address, so the address can't be confirmed; send to them at low volume, after your confirmed addresses.
Catch-all, explained
Some mail servers accept email for any address at their domain and sort it out later, which makes it impossible to confirm a mailbox exists from outside. We judge the likelihood from who hosts the domain's email: Google Workspace and Microsoft 365 reject unknown addresses by default, while forwarders and self-hosted servers often accept everything.
What this tool can't do
It checks the address and the domain, not the mailbox itself. A well-formed address at a real company can still be a person who left. Confirming the mailbox needs a conversation with the mail server, which is what a full email verifier does. Use this for a quick check; verify whole lists before you send.
How often to check a list
Email lists decay: people change jobs, companies close and inboxes are abandoned. A common estimate is that a B2B list loses around a fifth of its valid addresses a year, so a list that was clean six months ago isn't clean today. Check a list right before you send it, not when you buy or build it. Remove addresses that bounced in earlier campaigns for good, and don't try them again. If a list comes back with a high share of invalid or risky results, treat the whole source with suspicion: the rest of it is probably out of date too.
In mailzy
Verify whole lists before you send.
mailzy's Email Verifier checks every address with the mail server itself. Your first checks are free, and an unknown result is refunded.
Questions before you start.
Ask us on the chat if yours isn't here. A real person answers.
Does 'looks valid' mean the mailbox exists?
No. It means the format is right and the domain receives email. Only asking the mail server confirms the mailbox, which mailzy's Email Verifier does.
Why is a catch-all address risky?
The domain accepts every address, so nothing confirms this one is a real person. Some bounce later or are never read.
How many can I check?
Up to 100 at a time here. For whole lists, the Email Verifier has no limit.
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