Instant · browser-safe

Email syntax checker

Validate the structure of an email address before doing slower DNS or mailbox checks.

Checks length, local part, @ placement, domain labels and common syntax rules.

What this check does

Syntax validation answers one narrow question: does the address look structurally valid? It does not prove the domain exists or that a mailbox can receive mail. For that, use the full email checker.

Common invalid email formats

Missing @ symbols, repeated dots, a local part longer than 64 characters, malformed domain labels, and addresses without a valid domain suffix are rejected.