A recent field experiment investigated the impact of AI-assisted writing on recipient engagement in professional emails. The study involved 121 employees from six companies who sent emails under three conditions: unaided writing, GPT-5 rewriting in a playful tone, and GPT-5 rewriting in a standard tone, over a period of three weeks. The results showed that the use of playful tone in AI-assisted writing had a significant effect on recipient engagement1. The experiment demonstrated that AI can be used to craft emails that are not only informative but also engaging, which can lead to better outcomes in workplace communication. The study's findings have implications for the use of large language models in professional settings, highlighting the potential benefits of using AI to enhance the tone and style of written communication. This matters to practitioners as it suggests that AI-assisted writing can be a valuable tool for improving the effectiveness of email communication in the workplace.