Does it verify that an email address actually exists?

The validator checks syntax and MX record existence. Verifying that a specific mailbox exists requires an SMTP handshake, which most email providers block. Use a dedicated deliverability verification service for that level of checking.

Which RFC does the validation follow?

Validation follows RFC 5322 for syntax and RFC 5321 for the SMTP envelope address format, covering all practical email address patterns.

Can I validate a list of emails at once?

Yes. Paste a newline-separated list of addresses and the validator checks each one and reports results in bulk.

Best Free Online Email Validator

Invalid email addresses in your database cause bounce rates that hurt email deliverability and sender reputation. devtoolkit.sh's Email Validator checks email addresses against the full RFC 5322 specification, catching invalid characters, missing @ symbols, malformed domains, and excessively long local parts. It also checks that the domain has valid MX records, confirming that it is configured to receive email. Paste a single address or a list of addresses and get instant validation results. This is useful for cleaning imported contact lists, testing registration form validation logic, and auditing email databases before a campaign send.

FAQ

Does it verify that an email address actually exists?: The validator checks syntax and MX record existence. Verifying that a specific mailbox exists requires an SMTP handshake, which most email providers block. Use a dedicated deliverability verification service for that level of checking.
Which RFC does the validation follow?: Validation follows RFC 5322 for syntax and RFC 5321 for the SMTP envelope address format, covering all practical email address patterns.
Can I validate a list of emails at once?: Yes. Paste a newline-separated list of addresses and the validator checks each one and reports results in bulk.