Why it is harder than it looksThe inbox is the worst-structured interface in the company.
One message carries three intents. The order number sits in the third reply of a forwarded chain, the specification is in an attachment, and the word "urgent" has no field anywhere. Email is the interface nobody designed - and the AI has to meet it as it arrives, not as a form would have collected it.
The answer usually lives in three systems the mailbox cannot see. Order status in the ERP, the account's terms in the CRM, the batch result in the quality records. A model that reads only the email can be fluent, polite and wrong.
And guessing is unacceptable. A reply commits the business - a delivery date, a price, a statement about quality. Hallucination here is not a quirk, it is a liability. Which is why human-in-the-loop is a design requirement, not an admission of failure.