Press 7 to erase the current message and return to the previous message. Press the pound key at any time to hear this menu again. Voicemail systems provide no mechanism for quickly rewinding two seconds to hear a phone number again. Nor do they provide a way to save a message forever, analogous to taking the tape out of the machine and saving it for use later in court. Voicemail is, as far as I have been able to calculate, always more expensive than just buying everyone an inexpensive answering machine.
Voicemail is a non-distributed unreliable centralized complicated expensive disaster.
But it has a technological imperative, so they stuck it to me anyway. The Punch Line I was informed I'd be expected to attend a one-hour Voicemail Training Session. When I made it clear that the probability of my doing that was not well approximated by any positive number, I was sent a form to sign.