Greeting Messages For A Hen I Have An At&T Home Phone, How Do I Record A Greeting Message If I'm Not At The Phone?

I have an At&T home phone, How do I record a greeting message if I'm not at the phone? - greeting messages for a hen

I tried to press the record button and it's only a message for me. I called my phone several times only to receive an automated response. Can I change this and if so, how?