To change your voicemail message on iPhone: 1. On your home screen, tap Phone. 2. At the bottom, tap Voicemail on the menu bar. 3. Tap Greeting in the top left corner of your screen. 4. Tap Custom if you want to record a custom greeting. 5. To record a new greeting, tap Record. Tap Play to listen to it. 6. Lastly, tap Save in the top right corner.
On the iPhone, go into voicemail and tap "Greeting". Record a few seconds of something and tap stop. Before you tap save, use iFuntastic or SFTP to navigate to /var/root/Library/Voicemail on your iPhone. You'll see a file called "Greeting. amr". This is the audio you just recorded. Delete that file and replace it with your custom message which should then be renamed to "Greeting.amr". Tap "Play" on the iPhone to verify your message works. If it plays, tap "Save" and your custom message will be uploaded to AT&T's servers.

Verizon has become the ultimate network carrier out there and they have come up with plans to meet the diverse needs of the users. Similarly, there is a voicemail feature through which users will be able to access important messages if you couldn’t answer someone’s call.
When using a Cisco phone, you can record and change your voicemail greeting directly on the phone. For the following instructions, to select an option, you can use the phone's blue toggle button to scroll down and highlight the desired option, and then press the Select soft key. Press the Services (globe icon) button on the phone.