ChatGPT for Gmail is a free Chrome extension that leverages OpenAI's ChatGPT technology to boost your email writing efficiency and quality. It can generate subject lines based on your email content, create multiple subject line variations, draft email content based on your subject line, real-time check readability and spam scores, rewrite your entire email for improved clarity, and offer unlimited customizable prompts for creative emails and replies. It can also summarize email threads and help you craft personalized responses. Install the ChatGPT for Gmail extension and write emails like a pro, saving you valuable time.