What is the ruling on a young man addressing a young woman, and vice-versa, with words like "my dear" or "my darling" online?

The relationship between a man and a non-mahram woman is impermissible except within the framework of a legitimate marriage. Addressing them is also impermissible except out of necessity, and the conversation must be within the bounds of etiquette and morals, as Allah Almighty says: "And when you ask [his wives] for something, ask them from behind a partition. That is purer for your hearts and their hearts" (Quran 33:53). And His saying: "If you fear Allah, then do not be soft in speech [to men], lest he in whose heart is disease should covet, but speak with appropriate words" (Quran 33:32). This includes conversation and correspondence over the internet. Establishing friendly and acquaintance relationships between the sexes is forbidden and leads to corruption. Furthermore, a young man addressing a girl with "Ya al-Ghaliyah (O precious one)," or "Ya al-Habibah (O beloved one)," or "Ya al-Azizah (O dear one)," or vice versa, is among the reprehensible acts that are not considered appropriate speech; rather, it is a form of flirtation. Even if the conversation is for the purpose of inviting to Allah (Da'wah), it is more appropriate for men to limit their conversations to men, and women to limit theirs to women, to prevent temptation.