You don’t have to spell out every single thing that you think they might want to know. Have some faith that your callers will be able to figure things out on their own. Be natural but informative.
When you have finished recording your professional voicemail greeting, you may want to have a close friend call your phone number so you can listen to the outgoing message together. That way, you can get her opinion of the voice message before other callers are able to listen to it. If your friend recommends some changes for you, these should be easy to make, because most systems will allow you to delete your outgoing message and re-record it as many times as you would like. You might also Like Recommended lluviaporos December 5, 2013

Writing a script doesn’t mean you have to write a speech. A simple greeting is fine, like this sample voicemail message:
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.