I’m no legal expert but have worked with leases a bit. I wouldn’t be suprised if the landlord has a case. Even though there is no paperwork, there is still the email communication which can prove agreement and the fact that you’ve been paying rent could imply that you have both been acting under the assumption of a lease. However, your rent payment is probably more than small claims will allow, so landlord would have to take you to court and that would cost both of you lawyer fees. You could always meet somewhere in the middle if it comes to that, before court. Just curious, does landlord have the necessary permits to rent?