Hi there,
I am an expert JavaScript developer with more than two years of experience in Google Cloud based product development and automation. Your requirements are sound but, I disagree with the methodology. Here's why:
1. Smallest change in the UI will break your app and Google UI changes quite frequently
2. There are background bot fingerprinting processes running that makes it very difficult to ensure reliable performance
3. IP banning is inevitable and working around that will be quite costly with third party IP proxies
That being said, here's a workable and scalable model:
1. We implement a Cloud Function on Google Cloud that runs routinely and sets up other mail handling jobs for all functions that can scan all email addresses (call this the load balancing solution)
2. Each other function (call these handler function) receives a set of email addresses and scan them for new emails
For my strategy to work, you need to provide me two things:
1. A Google Cloud Project setup with Pay as You Go enabled to activate all features
2. You need to prepare the list of emails and their app specific password (you can create app password from Manage your account) in a JSON file (I will provide format)
3. The passwords will be updates by you when you have the full system so you can test; this will avoid any breach of confidentiality; I will use my own account for testing
Let me know what you think of my offer. Thanks for your time and consideration.