You cannot get a complete and specific answer to your question unless the documents are reviewed. The facts you state, however, do not form the basis for legal action on the part of the agent. If he has no contract, and if your exchange of emails or any other writing did not authorize him to represent you, then you owe him nothing. If you think he will follow through with his threat, then have your documents reviewed by an attorney. If you don't, then just ignore him. Whatever you do, no more emails. This is a time to remain silent and stop engaging with someone who wants money that you don't owe, according to your post.