Comforting the Mourners

1. There's two purposes of comforting the mourner. One is to comfort and speak to the living relatives who are very distressed. The other purpose is to show respect to the deceased. Comforting a mourner over the phone only fulfills the first purpose and even in that respect it's much better to go to the mourners house. Therefore, if a person can go to the house of the mourner he should not exempt himself by calling on the phone. However, if a person can't make it to the mourner's house because of an illness or involvement in a mitzvah there is an obligation to fulfill what he can by calling on the telephone.