Email Validator
Check whether an email address is written correctly and whether its domain is set up to receive mail. Each address gets a clear verdict with the reason behind it, so you know exactly what was tested and what was not.
- Encrypted connection
- No sign-up
- Free to use
How to use Email Validator
- Type or paste one address, or up to 50 with one per line (commas and semicolons also work).
- Select Validate.
- Read the verdict next to each address and open a row to see every individual check.
- Copy the addresses that look deliverable, or download all results as a CSV file.
Email Validator features
Precise format check
Finds missing @ signs, double dots, illegal characters, over-long parts and broken domains, and says which rule was broken.
Live domain check
Looks up the domain's MX records to see whether any mail server is published for it.
Typo suggestions
Recognises near-misses such as gmial.com or yahoo.con and suggests the likely intended address.
Disposable and role detection
Flags temporary inbox services and shared addresses such as info@ or support@.
Bulk validation
Up to 50 addresses per run, with duplicates removed and a summary of the results.
Honest about limits
States plainly that the mailbox itself is not contacted, instead of guessing whether it exists.
When to use Email Validator
- Checking an address someone dictated over the phone before sending an important message.
- Cleaning a small contact list before importing it into a newsletter tool.
- Finding out why a message bounced: wrong format, mistyped domain or a domain without mail servers.
- Testing the addresses your own sign-up form accepts or rejects.
Email Validator FAQ
Does this tool tell me whether the mailbox really exists?
No. It verifies the format of the address and that the domain publishes mail servers. Whether a particular inbox exists is known only to the receiving mail server, and most servers deliberately refuse to reveal it. The reliable way to confirm a mailbox is to send a message containing a confirmation link.
What does “Domain cannot receive mail” mean?
The domain has no MX record and no address record, or it publishes a “null MX” record that explicitly refuses email. A message sent to such an address will bounce, whatever comes before the @ sign.
Why is a correctly formatted address marked with a warning?
Warnings point to addresses that are valid but risky: a likely typo of a large provider, a disposable domain, a domain without MX records, or an unusual form such as a quoted local part that many systems reject.
Are plus signs and dots allowed in email addresses?
Yes. name+tag@example.com and first.last@example.com are valid. Dots may not appear at the start or end of the part before @, and two dots may not follow each other. Many characters such as ! # $ % & * + / = ? ^ _ are permitted as well, even though forms often reject them.
Are the addresses I enter stored?
No. The list is sent to our server to perform the DNS lookups, the results are returned to your browser, and nothing is saved or added to any list.
How long can an email address be?
The part before @ may be up to 64 characters and the whole address up to 254 characters. Each label of the domain, the pieces between dots, is limited to 63 characters.
What email validation can and cannot prove
An email address has two halves. The part after the @ sign is a domain name, and it must follow the same rules as any other domain: labels of letters, digits and hyphens separated by dots, ending in a top-level domain. The part before the @ sign belongs to the mail provider, and the standard is surprisingly permissive about it. A validator that only accepts letters, digits and dots will reject real addresses, while one that accepts anything containing an @ will let obvious mistakes through. This tool applies the actual syntax rules and reports the specific rule an address breaks.
Format alone says nothing about delivery, so the second step is a DNS lookup. A domain that wants to receive email publishes MX records naming its mail servers. If a domain has none, sending servers try its ordinary address record as a last resort, which works only occasionally. If neither exists, or the domain announces a null MX, delivery is impossible. These lookups are answered by the public DNS in real time, so the result reflects the domain as it is configured right now.
The final step, proving that a specific mailbox exists, is deliberately not attempted. Services that claim to do this open a connection to the recipient's mail server and begin a delivery without finishing it. Large providers answer “accepted” for every address to prevent exactly this kind of probing, others block or greylist the attempt, and repeated probing can get the sending server blacklisted. The answer is therefore unreliable in both directions. Treat a deliverable-looking result here as “nothing is wrong that can be detected from outside”, and use a confirmation email whenever you need certainty.
For forms on your own site, the same order makes sense: check the format while the visitor types, suggest a correction when the domain looks like a typo, look up the domain when the form is submitted, and send a confirmation message before treating the address as verified.