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 any provision of the internal revenue laws is, after such period or such date, delivered by United States mail to the agency, officer, or office with which such return, claim, statement, or other document is required to be filed, or to which such payment is required to be made, 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.
This section shall apply in the case of postmarks not made by the United States Postal Service only if and to the extent provided by regulations prescribed by the Secretary.
If any deposit required to be made (pursuant to regulations prescribed by the Secretary under section 6302(c)) on or before a prescribed date is, after such date, delivered by the United States mail to the bank, trust company, domestic building and loan association, or credit union authorized to receive such deposit, such deposit shall be deemed received by such bank, trust company, domestic building and loan association, or credit union on the date the deposit was mailed.
Any reference in this section to the United States mail shall be treated as including a reference to any designated delivery service, and any reference in this section to a postmark by the United States Postal Service shall be treated as including a reference to any date recorded or marked as described in paragraph (2)(C) by any designated delivery service.
The Secretary may provide a rule similar to the rule of paragraph (1) with respect to any service provided by a designated delivery service which is substantially equivalent to United States registered or certified mail.