The information you want to put in your voicemail greeting should be concise enough for your prospects to get every bit of information they need. Leave the relevant information in a clear and precise manner.
Lastly, the configuration is complex (especially if you have never dealt with these systems before) and the documentation is sparse. This package came from Telco Depot, however, and despite my having worked with similar system before, I did have 2 small problems which I called the tech support number about. The technicians were extremely helpful!! My issue only took about 20 seconds to solve and on my second call, the tech connected remotely to my computer and walked me through the configuration step I was getting wrong.

22. "Hi, you've reached [your name, the office of X company]. We're closed until [date]. Please leave your name and phone number and someone will return your call ASAP. Have a great [New Year's, Fourth of July, etc.]."
Polite greetings when picking up the phone make the whole call go much easier, even if you're only responsible for handing the phone over to someone else. To greet people on the phone, use formal introductions when you are at work or keep it casual when talking to your friends to have phone calls that start off on the right foot.