What is the ruling on saying salaam to a person to whom you are speaking on the phone, when you do not know whether he is a Muslim or not?.Praise be to Allaah.
The ruling is the same as when meeting him in person. If you know that he is a kaafir, then do
not initiate the greeting. But if you do not know, there is nothing wrong with that.
And Allaah is the Source of strength.