I am personally a bit surprised about the responses here. It is completely reasonable for this email to reach Daniel and is most likely an artifact of bad documentation by engineers in the company. At the scale this company is running the person/team sending out these emails do not have time to dig in and understand each dependency they are sending emails on.
The response is as simple as "What library/product does this email pertain to?", "Please see the licenses for the libraries or products in question.", and what Daniel responded with as well: "I would be willing the dig in further for specific questions with a support contract.".