If a woman has a need to speak to a man that is not one of her mahaarim, she may speak to him, but with a casual tone that has no softness or gentleness in it and not in a joking or laughing manner.
Rather, her speech must be ordinary and in accordance with what necessity dictates – i.e. a question and an answer – as per the need only.
She must not speak in a tone that appears friendly, laughing or teasing, or in a mellow or beautified voice, thus stirring the desires of the one who has a disease in his heart. This is based on Allaah’s saying:
“Then do not be soft in speech, lest he in whose heart there is a disease (of
fornication) should be moved with desire. But rather speak in an honorable
manner.” [Surah Al-Ahzaab: 32]
[Shaykh Al-Fawzaan, Advice to the Muslim Woman]