Solution: Poor sound quality is unlikely the fault of a reliable business voicemail service that uses VoIP technology, Baldwin says. So garbled voicemails are often due to callers’ poor mobile phone reception while leaving their message—and you may just need to call them back, assuming you can figure out their phone number. But if the problem does seem to be your voicemail, make sure you’re using a business phone and voicemail service that uses VoIP and not relying on, say, your mobile phone’s voice mailbox.
Recording voicemail greetings for your business or personal life requires a separate list of priorities, because they are being used for two distinct purposes and will be heard by two very different types of callers. I have a friend with two cell phones - one for work, and one for personal calls - and if you call both lines, you would never know it's the same person. While the message on his personal line might not be ideal, he took the time to record a professional voicemail message for his business phone, which makes it stand out.

Each number can handle 2 simultaneous calls at the same time. You can purchase additional voice channel at $15/channel. 1 voice channel is equivalent to 1 voice call.
If a customer hasn’t saved your number in their phone, they’re a whole lot less likely to listen to your message. They see there’s a voicemail, but if they don’t know who it’s from, they’re not going to listen to it. In eVoice’s 2013 survey, 82 percent of the respondents said they don’t listen to voicemails from unknown numbers.