How to fine tune the mode that Ai shows the email reply recommendations with user tone by reading his inbox

I am planning to work on the following idea:
My goal is to let the AI assistant produce email reply ideas using the user’s tone preferences.
How can I ensure that AI reads the customer’s email inbox and provides auto suggestions?

I appreciate the detailed explanation?

Thanks in advance
I appreciate your reply

Thank you
Ravi Susmith
ravisusmith@gmail.com