Why is there an "ELECTRONIC POSTMARK - CERTIFICATION OF ELECTRONIC FILING" for my federal return but not my state return?

I e-Filed my federal and New York State returns and received notice that they were accepted yesterday.

Today I printed my returns and there was an "ELECTRONIC POSTMARK - CERTIFICATION OF ELECTRONIC FILING" document for the federal return only in the .pdf file.

But there was no certification of filing for the New York State return.

Why not?

Thank you.