Hadith.4993 - Al-Hasan ibn Mahbub narrated from Aban, from Al-Halabi, from Abu Abdullah (as) that Imam (as) was asked about a married man who committed adultery with a woman, and three men and two women testified against him.
Imam (as) said
"The punishment of stoning becomes obligatory upon him. However, if two men and four women testify against him, their testimony is not accepted, and he is not stoned, but rather he is subjected to the prescribed punishment for a fornicator."