How to Verify an Email Is Real Without Sending One (Dev Guide) Published

Short summary

A practical guide to email verification layers: syntax validation, MX record checks, SMTP handshake probing, and disposable email detection. Syntax + MX checks catch ~90% of garbage input for free and should be the default for signup forms. SMTP-level checks are unreliable in practice; high-value transactional flows should use paid verification APIs instead.

• •Syntax + MX record check is the practical default for signup forms, catching most fake domains at zero cost
• •SMTP handshake verification is theoretically useful but unreliable in practice due to server behavior differences
• •Disposable email detection via open-source domain lists adds protection for email marketing sender reputation

Generated with AI, which can make mistakes.