To enable Visual Voicemail, you must create a password by accessing your voicemail and then record a greeting as follows: Access the Telephone app, select the Voicemail tab and tap Configure now. Select a password for your voicemail and tap Done. Confirm your password by re-entering it and tap Done. Select Custom if you wish to save a new greeting or Default if you don’t wish to edit your message. Tap Save.
I can’t answer the phone right now, but if you leave me a message with your name and phone number, I will return your call as soon as possible. You have reached Jim Bucki. I can’t take your call at the moment but please don’t hesitate to leave a message after the tone. I will return your call as soon as I am able.

Luckily, it's easy to save a voicemail from your iPhone, Android or old non-smart phone. Let’s start with iPhones.
The telephone systems have the feature named as Voicemail. VoIP is the best example of it. When a receiver is unable to pick up the phone, then the caller can leave the voice message on the receiver’s phone. In older telephonic machines, such messages were stored as a voice message directly, and the receiver can hear them later. In modern telephone systems, such info is being stored on the server of the service provider in the user’s mailbox. It is similar to email in which the messages are saved in the form of audio instead of text.