The basic rule of thumb is that callers should hear one of two things when they first connect with your voicemail — either an apology for not being able to answer the call or a “thank you” for having called. You can do both if you prefer, but keep it short and to the point.
This is the type of message you should aim for when you are recording an answering machine greeting at your place of business. Some people do need to leave other information for business salutations, such as office hours, and they may leave special messages when they’re on vacation. Name of the business, or your name can be important too, since people may want to be sure they’ve reached the right person or business. Answering machine greetings should be pleasant in tone.

Obviously, I need to update it. And if you haven't changed your voicemail greeting in over a year, you're likely in the same boat.
Here, the oncologist is busy consulting a patient, but he/she leaves ways for the callers to fulfill their needs right away. A lawyer’s office needs to maintain professionalism at all times in order to record the perfect voicemail greeting. Let’s look at an voicemail greeting script example.