N.Y. Lien Law § 11

§ 11. Service of copy of notice of lien. Within five days before or\nthirty days after filing the notice of lien, the lienor shall serve a\ncopy of such notice upon the owner, if a natural person, (a) by\ndelivering the same to him personally, or if the owner cannot be found,\nto his agent or attorney, or (b) by leaving it at his last known place\nof residence in the city or town in which the real property or some part\nthereof is situated, with a person of suitable age and discretion, or\n(c) by registered or certified mail addressed to his last known place of\nresidence, or (d) if such owner has no such residence in such city or\ntown, or cannot be found, and he has no agent or attorney, by affixing a\ncopy thereof conspicuously on such property, between the hours of nine\no'clock in the forenoon and four o'clock in the afternoon; if the owner\nbe a corporation, said service shall be made (i) by delivering such copy\nto and leaving the same with the president, vice-president, secretary or\nclerk to the corporation, the cashier, treasurer or a director or\nmanaging agent thereof, personally, within the state, or (ii) if such\nofficer cannot be found within the state by affixing a copy thereof\nconspicuously on such property between the hours of nine o'clock in the\nforenoon and four o'clock in the afternoon, or (iii) by registered or\ncertified mail addressed to its last known place of business. Failure to\nfile proof of such a service with the county clerk within thirty-five\ndays after the notice of lien is filed shall terminate the notice as a\nlien. Until service of the notice has been made, as above provided, an\nowner, without knowledge of the lien, shall be protected in any payment\nmade in good faith to any contractor or other person claiming a lien.\n