Without purchasing any equipment, you can turn your touchtone telephone into the most complete answering system available anywhere. Your call will be answered even when you are on a call. This is not true with answering machine. Voice Mail requires no special equipment or wires in your home. An answering machine can't call to deliver a message, but Voice Mail can.
Callers can review, append, or discard a message before delivering it.
An answering machine simply records the message whether your caller satisfied with it or not. During power outage, Voice Mail will continue to take messages, unlike answering machines which will stop functioning. While listening to a message, a voice mail user can move ahead or backward in increments. A voice mail user can selectively save or discard messages. Playback controls are easy to use with more options available than an answering machine such as saving an individual message.