There's no clean way to verify an email address. Here's what works anyway.

Short summary

Email verification beyond basic syntax checks requires SMTP probing, but modern mail servers defeat naive probes via catch-all domains, greylisting, and anti-probe behaviors. Real verifiers need proper IP infrastructure, fallback strategies, provider-specific rules, and port 25 access—a 99% accuracy claim is likely false.

• •Syntax validation and MX lookups only catch obvious errors; they cannot prove mailbox existence
• •Modern mail servers deliberately frustrate automated verification through catch-all routing, intentional delays, and provider-specific return codes
• •Production-grade verifiers require port 25 access, IP reputation management, and hardcoded logic for Gmail/Outlook/Proofpoint to approach true accuracy

Generated with AI, which can make mistakes.