Is it permissible for a woman to ask her friend about the well-being of her non-mahram husband and request her to convey her greetings to him?

There is no harm for a woman to ask another woman about the well-being of her husband or to ask her to convey her greetings to him, provided that there is no fear of temptation (fitna) and that neither party develops an attachment to the other. The fundamental rule is that a man's greeting to a woman, and a woman's to a man, is permissible when there is no fear of temptation. However, many jurists have prohibited it as a preventive measure (sadd al-dhari'a), especially for young women, as temptation is often not absent. The likelihood of temptation decreases when greetings are conveyed through intermediaries, but if temptation is suspected, then it is also prohibited. Aisha, may Allah be pleased with her, once asked Bilal about his condition, even though he was a non-mahram to her, which indicates the permissibility of both direct and indirect inquiries.