Email Validator (Syntax Check)
Check one or thousands of email addresses for valid syntax, catch domain typos like gmial.com, flag role and disposable addresses and copy a clean list.
This checks the format only. Whether a mailbox exists can only be confirmed by its mail server, which a web page cannot contact; sending a confirmation email is the reliable test.
| Input | Status | Notes |
|---|---|---|
| jane.doe@example.com | valid | |
| user@gmial.com | valid, check | did you mean user@gmail.com? |
| john..smith@example.org | invalid | two dots in a row |
| info@example.co.kr | valid, check | role address |
Before you import a mailing list or send a campaign, it pays to remove addresses that can never work. This validator checks each address against the email syntax rules (RFC 5321 and 5322 limits, allowed characters, dots, domain labels), suggests corrections for common typos such as gmial.com or naver.co, flags role accounts like info@ and known disposable-mail domains, removes duplicates and gives you a clean list to copy. Up to 100,000 addresses are checked in your browser.
How to use this tool
- Paste addresses one per line or separated by commas ("Name <address>" is fine too).
- Keep the typo, role, disposable and duplicate options on, or switch off what you do not need.
- Review the table: invalid rows say why, flagged rows say what to check.
- Copy the clean list.
Formula
local-part@domain · local ≤ 64 bytes · domain ≤ 253 characters, labels ≤ 63, letters/digits/hyphens · whole address ≤ 254
The local part may use letters, digits and !#$%&'*+/=?^_`{|}~- with single dots between them (not at the start or end), or a quoted string. The domain needs at least one dot and an alphabetic top-level domain; international domains are converted to punycode first. Typo suggestions use an edit distance of at most 2 against popular mail domains.
Example
From the five sample lines, jane.doe@example.com is valid, user@gmial.com is valid but probably a typo for gmail.com, john..smith@example.org is invalid (two dots in a row), info@example.co.kr is valid but a role address, and Jane.Doe@Example.com is removed as a duplicate. The clean list keeps 3 addresses.
Frequently asked questions
Does a valid result mean the mailbox exists?
No. It means the address is well-formed. Only the receiving mail server knows whether the mailbox exists, and many servers will not say. A confirmation email is the dependable test.
Are capital letters a problem?
Domains are case-insensitive. The local part is technically case-sensitive, but virtually every provider treats it as case-insensitive, so the tool treats different capitalisations as duplicates.
Why flag role addresses?
Addresses such as info@ or support@ go to shared inboxes or groups; marketing platforms often restrict them because they cause more complaints.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/email-validator/
Cite or embed this tool
kakaoCalc. (2026, November 8). Email Validator (Syntax Check). https://kakao.mobile/tools/email-validator/
“Email Validator (Syntax Check).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/email-validator/.
Paste this code into your page. The widget runs in your visitors' browsers, shows no ads and keeps a link back to this page. Embedding terms