I read the following story about a tzadekes who passed away: She refused to buy a telephone with caller i.d. WHY? Because she was afraid that someone would call her knowing she has caller i.d. and when she doesn't pick up the caller would think that she is being ignored and her feelings would be hurt.
Makes one wonder about all of those people who HAVE caller i.d. and when they see the number on the screen they decide if the person calling is worthy of being answered. Sometimes, not only don't people answer at that moment but they also don't get back to the caller. People aren't bad. They just don't realize that to answer the phone is a chesed as the caller obviously wants something. To ignore the caller is anti-chesed. This doesn't mean that one must answer every phone call no matter what one is doing. On the contrary, often it is not appropriate to answer at that moment. But to ignore a person completely is ..... rude.
At Mevakesh we don't like rude.