I am looking for an experienced developer to build an E-Mail Warm-Up System. The goal is to improve deliverability and sender reputation for new domains by using approx. 200 own accounts (Gmail, Outlook, GMX, Yahoo, etc.) that automatically communicate with each other. I will provide all e-mail accounts, access to Fyxer AI (or a similar AI), and a mass mailing provider (e.g., Brevo or alternative). I will handle the initial mass send myself. After that, the system should automatically simulate realistic AI-driven replies, delays, openings, markings, etc., so that providers register trustworthy, natural communication. The system should be scalable (20–200+ accounts) with backend (Python/Node.js), frontend (React/Vue.js), monitoring (SPF/DKIM/DMARC, reputation), and a dashboard with KPIs.