High-Volume Email Verifier Development

Python / Node.js Developer for High-Volume Bulk Email & Webmail Verifier (MX Lookup + SMTP Handshake) I need a robust bulk-email verifier that can chew through hundreds of thousands of addresses per run without falling over... (Budget: ₹1500 - ₹12500 INR, Jobs: API Integration, Backend Development, DNS, Node.js, Python, SMTP)