Sidemail Validator is a free online tool designed to check the validity of email addresses. It performs comprehensive validation checks including syntax verification, domain existence, DNS resolution, MX record validation, and optional SMTP handshake testing without sending actual emails.

The validator checks multiple aspects of email addresses including syntax correctness, domain and DNS verification, MX records confirmation, SMTP handshake capability, disposable domain identification, and common typo detection. These checks help ensure email addresses are properly formatted, belong to live domains capable of receiving mail, and aren't from temporary email services.

The tool works by allowing users to paste an email address and optionally select a deep SMTP check. It then performs a series of validation tests including syntax validation, domain resolution, MX record verification, and when selected, a safe SMTP handshake that checks if the mail server accepts the recipient without sending any message.

The primary benefits include improved email deliverability, reduced bounce rates, and faster list cleaning. Use cases include validating individual email addresses before sending important communications, cleaning email lists for marketing campaigns, and verifying customer email addresses during sign-up processes.

The tool targets users who need to verify email addresses including marketers, sales professionals, customer service teams, and anyone managing email lists. It integrates with bulk validation capabilities through a separate email list validation tool for handling larger datasets.