Free email list checker: find emails that will bounce
Paste addresses or upload a CSV. Find the ones that will bounce, throwaway addresses and typos like gmial.com, then download a clean list.
- Free, no signup
- Up to 10,000 addresses
- Addresses stay in your browser
- Clean CSV download
Names and other text are ignored; we pick out the email addresses. · Up to 10,000 at a time
Only the part after @ is sent to look up mail servers. Addresses stay in your browser and nothing is stored.
Email list checker in 3 steps
- 1
Add your list
Paste addresses in any format, or upload a CSV export. The email column is found for you and your other columns are kept.
- 2
We check every domain
Format rules run in your browser. Each domain is looked up once in public DNS for a mail server, and checked against throwaway and typo lists.
- 3
Download a clean list
Good only, Good + Risky, or a full report with the reason for every address, as CSV.
Everything that can be known without sending an email
Accurate checks only: an address flagged Will bounce really can't receive email.
Dead and fake domains
Domains that don't exist in DNS, like a misspelt company name, are caught before they cost you a hard bounce.
No mail server
Reads MX records, falls back to the domain's address as the email standard (RFC 5321) does, and checks that the mail server's own address exists.
Null MX
Domains that publish a null MX (RFC 7505) to say they accept no email, such as example.com, are marked Will bounce.
Throwaway addresses
Over 9,000 disposable email services, including subdomains, from a public, regularly maintained list.
Typos of big providers
Catches gmial.com, hotmal.com, yahooo.com, outlook.con and similar, and shows the address you probably meant.
Role addresses and duplicates
Flags info@, support@, noreply@ and other shared inboxes, and removes repeated addresses, ignoring capital letters.
Why emails bounce, and what a list check can catch
A hard bounce means the receiving side said the address can't get email, permanently. Mailbox providers count hard bounces against the sender. Keep them well under 2% of what you send; above that, Gmail, Yahoo and Outlook start treating your mail as coming from a sender who doesn't look after its list.
What this checker can tell for sure
Every email address ends in a domain, and a domain can only receive email if DNS says where to deliver it. The checker reads that from public DNS:
- No such domain. The domain isn't registered, often a typo of a company name. Every email to it bounces.
- No mail server. The domain exists but has no MX record and no address to fall back to, so there's nowhere to deliver.
- Null MX. The domain publishes a single MX of
., the standard way to say it never accepts email. - Missing mail server address. The MX record points at a host name that doesn't exist.
What it flags as risky
Some addresses can receive mail but are still a problem. Throwaway services such as Mailinator expire within hours. Typos of big providers, like gmial.com, either bounce or reach a stranger's catch-all inbox. Role addresses such as info@ reach shared inboxes with lower engagement.
What no free checker can promise
Whether a single mailbox exists, for example whether jane@company.com is a real person, can only be tested by talking to the company's mail server. Many servers accept every address (catch-all) or block these tests, so the answer is often a guess. This tool doesn't guess: an address marked Good has a valid format on a domain that accepts email, which removes the bounces you can know about in advance.
Next, make sure your own domain is set up to send: check SPF, DKIM and DMARC with the email deliverability checker, and run your subject line through the spam word checker.
Is the email list checker free?
Yes. It's free with no signup. Check up to 10,000 addresses at a time and download the clean list as CSV. Addresses never leave your browser, and nothing is stored.
What does the email list checker check?
Each address is checked for valid format, then its domain is looked up in public DNS: does the domain exist, does it publish a mail server (MX record) or a null MX that says it accepts no email, and does that mail server's address exist. It also flags throwaway (disposable) email services from a list of over 9,000 domains, likely typos of big providers such as gmial.com or gmail.con, role addresses such as info@ and support@, and duplicates.
Does it check whether the mailbox itself exists?
No. Checking a single mailbox means connecting to the receiving mail server and starting to send, which many providers block, rate-limit or answer the same way for every address (catch-all). Results from free mailbox checks are unreliable, so this tool sticks to what can be known for sure from DNS: addresses on domains that can't receive email will bounce, every time.
What do Good, Risky, Will bounce and Unknown mean?
Will bounce: the address is malformed, or its domain doesn't exist, has no mail server, or says it accepts no email. Risky: the domain receives email, but it's a throwaway service, a likely typo of a big provider, or a role address that's usually a shared inbox. Good: none of those problems. Unknown: the DNS lookup timed out or failed, so check it again later.
Is my list private?
Yes. The addresses never leave your browser. Only the domains (the part after @) are sent to our server to look up their mail servers in public DNS, and nothing is stored. The results and any CSV you download exist only on your device.
How many addresses can I check?
Up to 10,000 unique addresses at a time. Duplicates are removed first, and each domain is looked up once, so a list with mostly Gmail and Outlook addresses checks in seconds. For bigger lists, split the file and check each part.
Why are role addresses like info@ marked Risky?
Role addresses usually reach a shared inbox or a group. They're real and often fine for business email, but they tend to have lower engagement and more spam complaints, and some go to people who never signed up. Keep them if you know the contact; the Good + Risky download includes them.
Why does Gmail say an address with an underscore is invalid?
Gmail usernames can only contain letters, numbers and dots, so an address like jane_doe@gmail.com can't exist and will bounce. A plus tag such as jane+news@gmail.com is fine.
How does a clean list help deliverability?
Gmail, Yahoo and Outlook watch bounce and spam complaint rates. Hard bounces from dead domains and typos tell them a sender doesn't manage its list, which pushes later mail toward spam. Removing addresses that will bounce before you send keeps your bounce rate low and protects your sender reputation.
Keep going
Import your users without the bounces
Atlis tracks what every user does after signup and sends lifecycle emails automatically. When you import users from a CSV, the same list check runs first, so dead domains, throwaway addresses and typos never get an email.
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