Offer of accord followed by tender

§ 15-503. Offer of accord followed by tender. 1. An offer in writing, signed by the offeror or by his agent, to accept a performance therein designated in satisfaction or discharge in whole or in part of any claim, cause of action, contract, obligation, or lease, or any mortgage or other security interest in personal or real property, followed by tender of such performance by the offeree or by his agent before revocation of the offer, shall not be denied effect as a defense or as the basis of an action or counterclaim by reason of the fact that such tender was not accepted by the offeror or by his agent. 2. If executed by an agent, any offer required by this section to be in writing which affects or relates to real property or an interest therein as defined in section 5-101 in any manner stated in subdivisions one or two of section 5-703 of this chapter shall be void unless such agent was thereunto authorized in writing.