Email and message summarization also introduces new problems that don't happen when using a chatbot for questions and answers since through the process of summarization it removes information from the original text and may remove key information or mischaracterize the message. The ways it may do this stuff isn't exactly predictable either. It's also harder since it's not about proving that something is true or not based on outside sources, it's about it being accurate to what they said, which may not be provable to outside sources.