If you sound too relaxed or overly familiar, you're going to undermine both your and your company's credibility. People want to buy from an expert — not someone trying too hard to sound cool. So avoid coming off as too laid back and using too much slang, "um's," and "yeah's."
It is no surprise that your actual voice mail greeting must be delivered in the same way: Professional, clear, brief, and to the point. In a previous blog, "Marketing Messages on Your Cell Say You Mean Business," some techniques for making a professional voice mail greeting were discussed. There are many similarities between leaving a voice mail, and producing a voice mail greeting. You want your callers and receivers to hear a confident and professional person on the other end delivering a coherent message. You should introduce yourself to a prospective client in a personal way. An email doesn't generate much discussion, nor does it necessarily show you went the extra mile in contacting the client. Generating conversation. A professional, well conveyed voice message shows the voice mail receiver that you are confident and well-spoken, and that there is a person behind the message. Emails can be prepared, edited, and revised unlike voice mail messages An email or email chain thread is documentation of a conversation that can easily be referenced In an email you can include a phone number, address, website, etc that may be hard to remember or record through voice mail communication Emails can be forwarded, CC'ed, and blasted.

Deciding what to say in a voicemail can be difficult. Poor quality and unprofessional voicemails come in a lot of shapes and sizes. Great voicemails strike the right balance of being concise, friendly and professional, which can be hard to do if you don’t leave them all the time.
We could be in, we could be out. You could leave us a message and later find out.