@Silvia Barber I read through your reference link. Pretty much the two exceptions that could not be denied are airplane and rental property. In a way, any doctor can pretty much write off the ESA note to a patient. Landlord can't denied the residents by law with the ESA note.
As per my reference from mass.gov
Also landlord can't ask for any document or proof ... we can only ask 2 questions
you are allowed to ask (1) if it is a service animal required because of a disability, or (2) what tasks the animal performs. You cannot ask for documentation or certification that it is a service animal. Currently, there is no state or national certification available for service animals so businesses are not permitted to inquire if the animal is licensed or certified or whether the animal has identification papers.
1) They would answer "yest", then landlord can't ask details about disability, because it is a medical situation and confidential
2) The tasks are a, b, and c..
So really the law is stacked against landlord... the dog is in.
For my situation, I am having the constable sends them 30 days notice to quit tomorrow anyway. It would be a good experience to battle this out at court.