New York law is strict when it comes to preserving — and acting upon — a defense grounded on improper service. In a nutshell, and subject to other rules (which I invite you to contact me about), valid service of a summons on an individual occurs through:
- personal delivery;
- delivery to another person in your current home or business with follow-up mailing;
- affixing a copy to the door of your current home or business with follow-up mailing;
- delivery to a designated agent; or
- by any other manner that the court may direct.
If you take the position that service was not carried out properly, you must either make a timely pre-answer motion to dismiss the complaint, or alternatively, raise it as an affirmative defense in your answer and make a follow-up motion to dismiss the case within 60 days of serving the answer.
The court strictly enforces this rule. To seek an extension of that 60-day deadline you must establish "undue hardship," which appears to be a very strict standard. Protect yourself and make the motion to dismiss early!
See our prior blog, Legal Grounds for a Motion to Dismiss.
 CPLR § 308. Read the section for all of its requirements.