Mold by an air conditioner close to our garage

They have an air conditioner that is close to our garage & I am pretty sure it is causing mold all over the side of our garage,there side of shared fence& our shed. They have piled junk in there yard & do not cut grass so I think the mold is worse for that reason! Do you believe it! What do you think? I would move if I could find a house. DISGUSTING!!!!!