From the Android Mobile App: Click the More button at the top left of the mobile app. Select Voicemail. Click Folder with Music Icon located at the top of the mobile app. Click the Record button, give the recording a title, and click OK. The system will call your extension. Answer the call and follow the prompts to record your new greeting.
To change your Standard Voicemail greeting follow the directions below. Enter your password and the press # key. From Shoretel Communicator (You will need to have access to your Shoretel phone to record the message) In the menu bar, click More, then Prefereces. Your phone will turn on and beep. Begin your message.

The very first thing to be checked is, have you set up the voicemail earlier or directly recording the voicemail greeting? If you haven’t already set up the voicemail and unable to record voicemail greeting, then go to the top of the page and learn how to set up voicemail on the iPhone.
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.