Free Tool

Free Email Syntax Validator

Check Email Format & RFC 5322 Compliance Instantly

Validate email address syntax and detect formatting errors. Catch invalid characters, typos, and RFC violations before data entry.

RFC 5322 compliant
Instant validation
Always free

Enter an email address to test against RFC 5322.

Parsing the address…

What this check returns
Whether the address parses under RFC 5322
The local part and domain, split out
The normalised form of the address

What We Check

Our syntax validator performs comprehensive format verification.

RFC 5322 Compliance

Validates that the email follows the official email format standard.

Valid Characters

Detects invalid or disallowed characters in email addresses.

@ Symbol Placement

Verifies proper placement and count of the @ symbol.

Domain Format

Checks if the domain portion is properly formatted.

Length Limits

Verifies the address doesn't exceed maximum length limits.

Typo Patterns

Detects common email typos and misspellings.

Common Syntax Errors We Catch

These are the most common email syntax mistakes.

Missing @ Symbol

john.doe.com instead of [email protected]

Double Dots

[email protected] (consecutive dots)

Spaces in Address

john [email protected] (contains spaces)

Invalid Characters

john@doe%.com (contains %)

Missing TLD

john@domain. (no top level domain)

Domain Starting with Hyphen

[email protected] (invalid start)

Why Syntax Validation Matters

Syntax validation is the first line of defense for email quality.

First Line of Defense

Syntax validation catches obvious errors before other verification steps, saving time and resources.

Catch Typos Early

Identify misspelled or malformed emails during data entry or form submission, before they enter your database.

Prevent Form Submission Errors

Real-time syntax validation in forms prevents invalid emails from being submitted in the first place.

Improve Data Quality

Clean, properly formatted emails lead to better database hygiene and improved overall data quality.

Beyond Syntax

Syntax validation is just the first step. Even if an email passes syntax checks, it still needs to be verified for domain existence, mailbox deliverability, and other factors. Use our full email verification tool for complete validation.

Domain validation - does the domain exist?
SMTP verification - can the mailbox receive emails?
Risk detection - is the address risky or suspicious?

Recently checked domains

Domain profiles updated most recently. Each one carries MX records, the mail host, authentication status and a trust score.

dayrep.com Fakemailgenerator emailirani.ir yahoo.fr Yahoodns wwfontsele.com Bumpemail ezehe.com Mailserver kiabws.online qmail.host mrvpt.com
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Syntax is only step one. The full suite adds MX, SMTP, catch-all, gateway, and trust scoring — so you know if it'll actually deliver.

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What you unlock

  • Full deliverability + trust report
  • Bulk verification for full lists
  • API & MCP access for integration

The other free tools

Each one answers a different question about the same DNS. Pick by the question you have.

free email checker Syntax, domain, MX, disposable and catch-all state for one address disposable email checker Whether the domain is in our disposable pool, and which provider runs it email enrichment tool Company, website, social profiles and web tech stack where we hold them MX record lookup MX hosts in priority order, and the mail provider behind them email domain checker MX presence, provider, and our disposable / free / company verdict catch-all domain checker Whether the domain is accept-all, and why that makes verification inconclusive SPF record checker Whether an SPF record is published, plus the provider it authorises DMARC record checker The DMARC record and its p= policy — none, quarantine or reject

Frequently Asked Questions

RFC 5322 is the official Internet standard that defines the format for email messages. Our validator checks compliance with this standard to ensure emails follow proper formatting rules.
Yes! An email can have perfect syntax but still be invalid if the domain doesn't exist, the mailbox isn't real, or the address is from a disposable email service. Syntax validation is just the first step.
Allowed characters include: letters (A-Z, a-z), numbers (0-9), and special characters like dots (.), hyphens (-), and underscores (_). Spaces, commas, and other special characters are not allowed.
The maximum length for an email address is 254 characters total. The local part (before @) can be up to 64 characters, and the domain part can be up to 255 characters.
No. A valid email must have exactly one @ symbol. It separates the local part (username) from the domain part. More than one @ or none at all makes the email invalid.
Yes! This email syntax validator is completely free. No signup, no credit card, unlimited checks. Validate as many emails as you need at no cost.

Validate Email Syntax Free

Check email format and RFC 5322 compliance. No signup required. Unlimited free checks.

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