New York Codes, Rules and Regulations
Title 12 - DEPARTMENT OF LABOR
Chapter IV - Resolution of Labor Disputes
Subchapter A - Labor Relations Board
Part 255 - Service of Papers
Section 255.1 - Method; proof

Charges, petitions, orders and other process and papers of the board, its members, agent or agency, may be served electronically, personally, by regular mail, by registered mail, by commercial mail service, or by leaving a copy at the principal office or place of business of the person to be served. A declaration or affidavit of service, setting forth the manner of such service, the return post office receipt when registered and mailed as aforesaid, or electronic confirmation shall constitute proof of service. Final orders issued by the board shall be served upon the parties by registered or certified mail, or pursuant to § 250.11 of this Chapter.