The ruling on kissing and shaking hands with one’s uncle’s or maternal uncle’s wife

Question:
Is it permissible for me to greet my uncle’s wife—by Allah, I know that the greeting here is a kiss—or my maternal uncle’s wife on the face?

Answer:
Your uncle’s wife and your maternal uncle’s wife, no, they are not mahram (relatives one may not marry) to you. So your uncle’s wife, your maternal uncle’s wife, and your brother’s wife, none of them are mahram to you. It is not permissible for you to greet her on the face, nor is it permissible for you to shake her hand. But the greeting from a distance by words: you greet her with words: “As-salamu alaykum” (Peace be upon you), and she says, “Wa alaykum al-salam” (And upon you be peace), “How are you, so-and-so?”