Just in case you fall victim to mumbling or speaking softly in your voicemail message be sure to repeat your contact information at the beginning AND end of your message so that the listener is more likely to be able to pick up on the information. This helps if you are speaking quietly or if the listener was not ready to record your information when you said it the first time. Repeating your information will save the listener time as they will not have to listen to your message again to get those details.
Many businesses want to sound professional and, as a result, end up creating boring, monotonous, and overly generic messages such as: “Hi, this is Joe. I’m either on the phone or away from my desk. Please leave me a message.”

Before any business can create clear, easy to hear (and understand) recorded audio messages, they need the right recording equipment. Many businesses try to get by with using audio recorded on a standard recording device.
As the odds of receiving a call back from your voicemail message are already low, you need to be very specific about what you say in your voicemail to give you the greatest chance of getting a call back. What you absolutely do NOT want to do is make yourself sound like a salesperson making a cold call. Instead, you want to sound like a very confident business colleague who deserves the respect of getting a call back.