Section 326 - Service of notices, orders and summonses1. Every notice, order or summons relative to a dwelling shall be served five days before the time for compliance therewith. The posting of a copy of such notice, order or summons in a conspicuous place in such dwelling, together with the mailing of a copy thereof, within five days of such posting, to each person whose name has been filed with the department of health or the department charged with the enforcement of this chapter, in accordance with the provisions of section three hundred twenty-five, at his address as therewith filed, shall be sufficient service thereof, except as provided in subdivision three.2. Except as provided by the provisions of this chapter which are less restrictive than the provisions of this subdivision, if any notice, order or summons is directed to any person pursuant to any provision of this chapter, including the provisions of subdivision two of section three hundred nine, and if the address of such person is not registered or, in any case for which personal service is provided, if such person cannot with due diligence be served personally, then such notice, order or summons may be served by posting a copy thereof in a conspicuous place upon the premises within which a violation is alleged to have been placed or a condition complained of is alleged to exist, and by sending a copy thereof by registered mail, return receipt requested, addressed to such person at his last known address or place of residence.3. In the case of a summons if the address of any agent or lessee whose name and address have been filed in accordance with the provisions of section three hundred twenty-five is in the city in which the dwelling is situated, then a copy of the summons shall also be delivered at such address to a person of lawful age, if upon reasonable application admittance can be obtained and such person found; and provided also that personal service of the summons upon the owner of such dwelling shall be sufficient service thereof upon him.4. Notwithstanding any inconsistency with this section, in a city, having a population of one million or more, a local law may provide for the manner of serving civil process for the enforcement of penalties, sanctions and remedies provided in such local law.N.Y. Mult. Dwell. Law § 326