As a matter of fact, some reports that have explored the decline of voicemail say the service is really only used by two types of people anymore: older parents and business people. But that still doesn’t lessen the annoyance of the receiver when they have to listen to the voicemail from mom and pop or the used car sales guy.
Avoid background noise. Whether you have music playing in your office, or you’re sitting in a coffee shop, background noise can make it difficult for your customers to understand your greeting. Limit the noise around you when you leave your voicemail greeting.

From the home screen of the online dashboard, find the recorded voicemail you wish to edit and click the Details button and then click Edit.
Once you have your new iPhone in hand and you are learning how to use it, one of the first things you may want to do is record a voicemail greeting. You have the option of using a default one that tells the person what number they have called, but you may elect for a more personal option.