We are trying to develop a new software product that requires an integrated email client. We found some old patents from Google regarding email systems.
https://patents.google.com/patent/US9819624B2/en https://patents.google.com/patent/US7818378B2/en https://patents.google.com/patent/US7912904B2 https://patents.google.com/patent/US8150924B2/en
We are trying to understand whether creating an email client similar to Gmail (with conversation threads and labels) will get us into trouble with Google later on. Yahoo Mail is a similar product to Gmail, for example. We are not sure to what extent having conversation threads in an email client is patented.
How can we avoid a legal conflict with Google, considering that we want to create a better product, not worse ?