RAG a 40GB Outlook inbox - Long term Staff member leaving, keeping knowledge (theory)

I've been fascinated by this concept since the early days of AI, and using ChatGPT has made it feel incredibly achievable and only just understood the concept of RAG. The idea is to leverage a local LLM paired with an open web UI to create vector or other databases of the inbox

My vision is to take something like a 40GB PST file, process it over a few hours, and produce a final database to give to huggingface . The goal is to preserve knowledge from a 10-year employee leaving the company by capturing the insights contained in their communication. This system could then handle incoming queries by checking if similar issues have already been addressed.

could imagine having outlook inbox open and as you get a question it reads it and can preprompt with a smart suggestion reply and why it came up with it,,, that be long term for now just chatbot to ask the query and if it knows.

Has anyone attempted something like this? If so, did you find it practical or beneficial?