How to validate emails properly in your app (beyond regex)

Regex-only email validation is insufficient because syntactically valid addresses may have non-existent domains, disposable mailboxes, typos, or role-based prefixes. Proper validation should check RFC 5322 format, MX records, SMTP mailbox existence, disposable/role detection, and typo suggestions. The article demonstrates an Email Validator API that returns a quality score (0–1) enabling nuanced accept/flag/block decisions, with support for single and batch validation.