Section 703 - Letters evidence of authority; effect of appeal1. Subject to the provisions of the succeeding section, letters granted by the court are conclusive evidence of the authority of the persons to whom they are granted until the decree granting them is reversed or modified upon appeal or the letters are suspended, modified or revoked by the court granting them.2. A certificate of letters testamentary or of administration duly issued by the clerk of the court shall be sufficient evidence, subject to the provisions of subdivision one hereof, of the existence of such letters and the identity of the fiduciary for all purposes for six months after the date of such issuance.N.Y. Surr. Ct. Proc. Act Law § 703