If your answering system lets you supply your own mp3 or wav audio files for the greetings, consider hiring a pro to record it for you.
After helping tens of thousands of companies set up voicemail systems, we’ve learned that there is no set of rules defining what makes a great business voicemail, but there are definitely some key points that you should aim to hit. Before you hit the record button for your voicemail message, take some of these tips into account:

Humor also leaves a lot of room for misinterpretation—which subsequently weakens sincerity and authority. A caller can be very turned off by merely misinterpreting your joke. Why take this risk? Additionally, this could even cause callers to question your character. Say, for example, the president of a company’s mobile phone voicemail greeting was funny. What’s to happen if the caller didn’t like or get the joke? What if they found it offensive? Another scenario is that a caller is reaching out to you for the first time—i.e. they have no idea regarding your personality. What next? The point is, with this type of greeting, humor is bound to be more divisive so just avoid it altogether. c. Poorly Pacing Your Message and Bad Time Management: Don’t speed through your message. Speak clearly so callers know what to include in their message and when to leave the message. At the same time, don’t drag your message out. No one wants to sit through a diatribe. Just get to the point clearly.
Cool Telecom voicemail includes VmX™ Locator technology. When someone gets your voicemail greeting instead of you, they can dial several options to get faster help. Dialing ZERO will ring the operator. Dialing ONE will get you someone else in the office. While dialing TWO will attempt to transfer the call to your cell phone. VmX™ Locator is a standard feature available with all of our systems, both physical and cloud-based.