Is it permissible to shake hands with males?

It is not permissible for a Muslim woman to shake hands with a man who is a stranger to her (i.e., not a mahram (definition)), due to the Prophet's (peace be upon him) saying: "For one of you to be stabbed in the head with an iron needle is better for him than to touch a woman who is not lawful for him," and Aisha's (may Allah be pleased with her) statement: "The hand of the Messenger of Allah (peace be upon him) never touched the hand of a woman who was not lawful for him." Therefore, handshakes between non-mahrams are forbidden, considered reprehensible acts, and bad customs.