What are the limits of interaction between a man and a woman who are not mahram to each other, and what is the ruling on showing appreciation, offering services, and giving advice to a man who is not mahram, in terms of whether it is recommended or disliked?

The relationship between a man and a non-mahram woman is legally restricted. Speaking between them is permissible when there is a need and when there is no fear of temptation; otherwise, it is prohibited. The ruling on speaking between them varies according to the need and the absence of temptation. As for rewarding kindness with supplication (dua), there is no difference between a man and a woman in this regard.