(b) Timely mailing. -- If any return, claim, statement or other document, required to be filed, or any payment required to be made within a prescribed period or on or before a prescribed date under authority of this article or the provisions of any article of this chapter imposing any tax administered under this article, is, after such period or such date, delivered by United States mail to the Tax Commissioner or the state Tax Department, the date of the United States postmark stamped on the cover in which such return, claim, statement, or other document or payment is mailed shall be deemed to be the date of delivery or the date of payment, as the case may be, provided the following mailing requirements are met:

1. (1) The postmark date falls within the prescribed period or on or before the prescribed date for filing (including any extension granted for such filing) of the return, claim, statement or other document, or for making the payment (including any extension granted for such payment); and
2. (2) The return, claim, statement, other document or payment was, within the time prescribed in subparagraph (1), deposited in the mail in the United States in an envelope or other appropriate wrapper, postage prepaid, properly addressed to the Tax Commissioner or the state Tax Department.