Hello, you have reached the dental office of Dr. X. We are busy assisting a patient now, but will call you back as soon as possible. Please leave your name, reason for calling, and your number. If this is an urgent enquiry, please call 911. In this case, the dentist is giving a reason for not being available and they’re providing a way to prioritize the patients who need the most help. They’re also leaving an emergency number for the most severe of situations.
Phones are assigned to people or to office names. For example a phone could show “MAU Plaza” or it could show a user’s name. If the phone is assigned to you, it will have your UNI email address associated with it. There are various kinds of voicemail greeting options in the new UNI Voicemail system. When you initialize your voicemail box for the first time, the system has you set up two of your default greetings, which consists of your (external) personalized greeting and your name greeting. You can access your greetings via phone or via the UNI voicemail web portal.

That's why I would definitely resist any temptation to leave any kind of joke message, even if it seems very clever, suitable or relatively benign. People might love it the first time they hear it. The eighth time is definitely going to annoy them. Fa5t3r December 4, 2013
People have short attention spans these days, and you should always craft your communications for the lowest common denominator with something as universal as your voicemail.