Email checker: find out if an email address is valid
Check or verify any email address online for free. Paste it in to test the format, the mail server and the mailbox itself. On catch-all domains, this email checker keeps going and returns valid or invalid.
Mailbox Verification
Ready to verify mailbox
Enter a corporate or consumer address in the console input to check whether the mailbox exists.
No signup, no card. One address per check.
Need more checks? Create an account and get 1,000 free credits. No card needed.
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How to check if an email address is valid
A full email check, also called email verification, has four stages. Checkers that only do the first one are the reason so many "checked" lists still bounce.
- 1
Format
Is the address well formed: one @, a valid name before it, a domain with an ending such as .com. This catches typos and nothing else.
- 2
Mail server
Does the domain publish mail server (MX) records. No MX records means no mailbox can exist there, so the address is dead before any message is sent.
- 3
Mailbox
The checker asks the mail server whether this mailbox exists, without sending an email. A yes means the mailbox exists. A no means it is not there.
- 4
Catch-all
If the server also says yes to a made-up address, step three proved nothing. This is where most email checkers print "catch-all" and stop. Giggal.ai runs extra signals that separate a real mailbox from an accept-all reply and returns valid or invalid.
Giggal.ai
The result panel above shows each stage as it runs. To check email address validity, paste the address in and press the button. One address takes a few seconds.
What the email checker shows for each address
Each check ends in one of three results.
Valid
The mailbox exists and passed the extra signals, so mail sent to it should arrive.
Invalid
The address has a broken format, no mail server, or the server rejected the mailbox. Mail sent to it will bounce.
Unknown
Rare here. The server did not answer in time or delays new senders on purpose. Check it again later rather than treating it as dead.
Under the result, the email address checker lists the details a deliverability decision depends on:
The mail provider (Google Workspace, Microsoft 365, or a gateway such as Proofpoint)
The mail server that answered
Whether the address is disposable (a temporary inbox that will vanish)
Whether it is role-based (info@, sales@, support@, which reach a shared inbox, not a person)
Whether it sits on a personal mailbox provider like Gmail or Yahoo, which matters when you qualify B2B leads
How to check if an email address exists
An email address exists when its mailbox is set up on the receiving mail server and accepts mail. To verify the email address, the email checker asks that server directly, without sending a message. It proves the mailbox is there. It does not prove who owns it or how often they read it.
If you are not sure whether an address in your contacts exists, check it in the email checker above.
Addresses that do not exist usually show one of these signs:
Typo domains such as gmial.com or yaho.com, which have no mail server or reject everything.
No mail server records on the domain, so there is nowhere for mail to go.
A rejected mailbox: the domain is real, but the server says this person is not there, often because they left the company.
Random strings before the @, typed by bots or by people filling in a form they did not want to complete.
Why verify an email address before you send
Mail sent to an address that does not exist comes back as a hard bounce. Gmail, Outlook and other mailbox providers count your bounces. When too many of your emails bounce, they trust your sending domain less, and more of your mail goes to spam or is blocked, even mail sent to real people. Email verification finds those addresses before you send.
Read hard bounce vs soft bounce for what each bounce code means and what to do with it.
- <3%
Lower bounce rate.
Lists cleaned with Giggal.ai usually bounce under 3%.
A healthy sender reputation.
Fewer bounces keep your domain in good standing with mailbox providers.
Better deliverability.
A good reputation means more of your emails reach the inbox instead of the spam folder.
Cleaner data.
Dead addresses come out of your CRM before they cost you time or sending credits.
When to use an email checker
Use this email checker tool whenever one address decides what you do next:
Before you reply to an inbound lead whose address looks typed by hand.
When a signup bounces and you want to know if the address ever existed.
Before you send to an address you found on a website or in a CRM.
To test one address from a purchased list before you pay to clean the whole file.
To confirm a contact on a catch-all domain that another tool marked "risky".
Why other email checkers stop at catch-all
Some company mail servers accept every address, real or made up. That is a catch-all domain. Ask it about a real employee and it says yes. Ask it about a name you invented and it says yes to that too. So the normal mailbox check proves nothing there.
Spotting a catch-all domain is easy: test one made-up address and see if it is accepted. That is why almost every email checker can tell you a domain is catch-all. Finding out which mailboxes behind it are real takes far more work, so most email verifiers stop at the label and leave the decision to you. On B2B lists, catch-all addresses are often a large share of the contacts, and many of them are real people.
Giggal.ai runs the extra signals on every catch-all address and returns valid or invalid, which is also why this page allows only a few checks per visitor. Read what a catch-all email address is for the full background.
Check a whole list instead of one address
The email checker on this page handles one address at a time. For bulk email verification of a list, create an account, upload a CSV or Excel file of up to 50,000 addresses, and clean your email list with the same checks on every row. You start with 1,000 free credits and no card.
To check addresses inside your own app or signup form, use the email verification API. It runs the same checks and returns the result as JSON.
Email checker FAQ
An email checker tells you whether an email address is valid by checking its format, its mail server and the mailbox itself. It is also called an email verifier or email validator. It works without sending an email to the address.
Yes. Email checker, email verifier and email validator are three names for the same kind of tool. All of them verify an email address by checking its format, its mail server and the mailbox. They differ on catch-all domains. Many stop there with "risky". This one returns valid or invalid.
It runs four checks in order. First the format of the address. Then the domain's mail server records. Then it asks the mail server whether the mailbox exists. On catch-all domains, where the server says yes to every address, Giggal.ai runs extra signals to tell a real mailbox from a fake one.
Paste the address into the email checker at the top of this page and run the check. You get a result in seconds: valid, invalid or unknown, with the reason and the mail server details underneath.
Yes. The email checker asks the receiving mail server whether the mailbox exists and stops before any message is sent. Nothing lands in the person's inbox.
No. The check talks to the mail server only. The owner of the address never receives anything and is not told that the address was checked.
It depends on the checker. Most are accurate on normal domains and give up on catch-all domains, where they return "risky" or "unknown". Giggal.ai keeps going on catch-all domains and returns valid or invalid, and measures 98.5% accuracy on business lists.
That the mailbox was confirmed, not just that the domain accepted the recipient. A plain catch-all label only tells you the server says yes to everything. Valid here means the address passed the extra checks that separate a real mailbox from one that will bounce.
The mail server did not give a clear answer in time, often because it delays new senders on purpose (greylisting). The address is not proven dead. Check it again later.
A few each hour, with no signup and no card. Each check runs the full set of checks, which is why the number is small. To check more, create an account.
Yes, but rarely. A valid result means the mailbox existed at the moment of the check. Mail can still bounce if the mailbox is full, if the mail server is down for a while, if the person leaves the company after the check, or if the server blocks your sending domain. Check addresses close to the time you send.
Giggal.ai is run by TargetPulse Ltd and handles personal data under the GDPR. The privacy policy at giggal.ai/privacy-policy explains what is collected, how it is used and how long it is kept.
Not on this page. Create an account, upload the list as a CSV or Excel file, and every address gets the same checks. You start with 1,000 free credits and no card.
Check your whole list
1,000 free credits, no card required.