Is it permissible to respond to the ex-husband who utters sweet words, knowing that the divorce was due to his other wife and his lack of interest in the questioner, and does the presence of a handkerchief with traces of his makeup and his fluids raise suspicion?

If a man divorces his wife and her 'iddah (definition) (waiting period) expires, she becomes a stranger to him. It is permissible for him to be kind to her with money without any Sharia (definition)-related reservation. However, speaking with her unnecessarily is a reprehensible act and a cause for temptation. Jurists have stipulated its prohibition, as speaking with a young woman who is a stranger is impermissible without need. If a man greets her, she should not return the greeting to avert corruption. If the divorce was an irrevocable minor divorce (one or two pronouncements), he may marry her again with a new contract and a new mahr (dowry). If it was an irrevocable major divorce (three pronouncements), she is not lawful for him until she marries another man willingly, and he divorces her after consummation. Regarding the handkerchief mentioned, its meaning or the timing of this action is unclear.