N.Y. Gen. Oblig. Law § 15-503

§ 15-503. Offer of accord followed by tender. 1. An offer in writing,\nsigned by the offeror or by his agent, to accept a performance therein\ndesignated in satisfaction or discharge in whole or in part of any\nclaim, cause of action, contract, obligation, or lease, or any mortgage\nor other security interest in personal or real property, followed by\ntender of such performance by the offeree or by his agent before\nrevocation of the offer, shall not be denied effect as a defense or as\nthe basis of an action or counterclaim by reason of the fact that such\ntender was not accepted by the offeror or by his agent.\n 2. If executed by an agent, any offer required by this section to be\nin writing which affects or relates to real property or an interest\ntherein as defined in section 5-101 in any manner stated in subdivisions\none or two of section 5-703 of this chapter shall be void unless such\nagent was thereunto authorized in writing.\n