A woman asks: If I am in a state of wudu' (ablution) and a non-mahram man greets me, does that affect the wudu'?

Question:
She says: If I am in a state of wudu' and a non-mahram man greets me, does that affect the wudu'? May Allah reward you with good.

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds, and may Allah send prayers and blessings upon our Prophet Muhammad, his family, and his Companions. As for the fact that she intended to shake hands with him—meaning she shook hands with him—shaking hands with a woman by a man who is not a mahram to her is not permissible, neither in a state of wudu' nor otherwise, because that is a cause of fitnah (trial, discord or temptation).
As for if a man touches her while she is in a state of wudu', or if he is in a state of wudu' and touches her with desire, then that is also forbidden and it invalidates the wudu'. If this man is not a mahram to her, it invalidates the wudu'. If this man is not a mahram to her, it is forbidden and it also invalidates the wudu', so two prohibitions are combined in it. As for if it is her husband, if it is with desire, it invalidates the wudu', and if it is without desire, it does not invalidate the wudu'. The conclusion is that if the one who shook hands with the woman is a non-mahram to her, then this is forbidden, and if it was with desire, it invalidates the wudu'. As for if it was from one of her mahrams or from her husband and it was not with desire, then it does not invalidate the wudu' and there is no sin in it. As for if her intention with the greeting was merely to exchange the greeting with words and she responds to him with words, then this is prescribed and it does not affect the wudu'.