1960—Puspan. L. 86–507 inserted “or by certified mail” after “registered mail”, and “or receipt for certified mail” after “registry receipt.”

“United States Postal Service” substituted in text for “Post Office Department” pursuant to Puspan. L. 91–375, §§ 4(a), 6(o), Aug. 12, 1970, 84 Stat. 773, 783, which are set out as notes preceding section 101 of Title 39, Postal Service, and under section 201 of Title 39, respectively, which abolished Post Office Department, transferred its functions to United States Postal Service, and provided that references in other laws to Post Office Department shall be considered a reference to United States Postal Service.