Your mentor, David, founded a company that shut down four months ago after 7 years. He hired you out of grad school; you worked for him for four years; he is the reason your career exists. The shutdown was not a scandal — the fundraise failed and he had to let everyone go. He has been quiet on LinkedIn and isn't responding to most messages. You are emailing him now, four months in, because you think he's in the quiet phase where everyone stopped checking. You are not asking for anything. 180-260 words. Just the email body, no preamble.