Also, carriers have a limit to how long they'll let you record a voice mail. Test it with your phone and a friend before you trust this method.
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.

I got a new cell phone recently. As the world stood in line to pick up the latest iPhone 8, I graduated to the 6S. I pride myself on that actually. As with all new phones in the 21st century, the voicemail must be set up anew. I used the default message for the first few days, but finally settled down to record a more personal greeting.
On your iPhone, go to the Phone app and tap the Voicemail icon. 2. Choose a greeting and password and click Set up. 3. Then, confirm the voicemail password you just created. Ideally, passwords will contain no more than seven digits, but at least four. 4. You may choose between default or custom greeting on the next screen. Pre-selected defaults