If Set Up Now doesn’t appear, then that means your phone has been set to the automated voicemail option. You can change it whenever you like, though. All you have to do is tap Greeting, which should be at the top-left of the screen.Tap Record, and then speak slowly and clearly into the phone so that your message is recorded.When you are finished, hit Stop.
Your message is a period of time that they are forced to wait through in order to do what they called to do in the first place — relay information to you.

When your phone only rings once then cuts out, this fault is known as "ring trip". It can be caused by a number of things either inside or outside your property, and will require a process of elimination to track down the cause of the fault.
To get the most out of your voice mail it’s important that you properly set up your personal mailbox. Press the voice mail button on your phone and enter your password (0 0 0 0 by default). Press 5 from the mailbox menu. Press 1 to assign your no answer greeting Press 2 to edit the greeting, begin recording when prompted. A typical greeting says “Hi, you’ve reached Mitch Scott. I am currently on the other line or away from my desk. Please leave your name number and a brief message and I will return your call as soon as possible.” press # when finished. Press 1 to set this as your active greeting Press 5 to edit mailbox greetings Press 7 to record your mailbox greeting and follow the prompts to record your mailbox greeting (You can repeat the greeting you used in step 3). Press # when finished. Press # from the main menu Press 7 for personal administration Press 2 to record your name “Mitch Scott” press # when finished Press # from the main menu Press 7 for personal administration Press 3 to enter your directory name Press 2 and follow the instructions to enter your name in the directory Press # from the main menu press 7 for personal administration Press 1 to change your password Press 2 and follow the instructions to change your password.