Prior to returning to Motown, Dobbins left the group due to her growing family and her father, who advised her not to continue her career in show business. Dobbins' departure left Horton in full charge of the group. To replace her, Horton asked another Inkster graduate, Wanda Young, to replace Dobbins. When the group returned and performed their composition, Gordy agreed to work with the group but under the advice that they change their name. Gordy renamed them The Marvelettes and signed the act to Motown's Tamla division in July 1961. The following month, the group recorded "Please Mr. Postman", which was polished by Brian Holland, Robert Bateman and Freddie Gorman, another songwriting partner of Holland (before Holland became part of the Holland–Dozier–Holland team), who moonlighted as a mailman, as well as the song "So Long Baby", sung by Wanda. Tamla issued "Please Mr. Postman" on August 21, 1961. The song then climbed to the top of the singles chart, reaching #1 that December. making them the first Motown act to have a #1 hit on the Hot 100.