While missed calls aren’t ideal, you can let your caller know you’re still there for them by having a great voicemail greeting. The best business voicemail greetings let your customers (and potential customers) know why you’re not available and how they can best get in contact with your business. They are also short and to the point. You usually want to keep your greeting between 6 and 24 seconds long so callers don’t hang up halfway through.
Most of the time this error is caused by the connectivity of your phone to a cellular network or WiFi connection. The easiest way for solving this issue is by turning the Airplane Mode ON. On your main screen of the phone, you can swap down the notification bar and tap on the Airplane Mode option. Once it is ON all the connectivity to your phone will be turned off. You can wait for 30 seconds and then turn it back OFF by using the same method. This option can vary depending on the device you are using. For some devices, you need to go to settings or use the power button on the phone to get to Airplane Mode. After applying this method, you can now try updating or setting up the voicemail greeting on your phone.

That way you'll get to know exactly what other people hear when they call your phone and one last thing I wanted to show you. If you don't see that play on record option on the bottom, you don't have visual voicemail. Set up on your phone and that's through your provider. So if you have at and T sprint T-Mobile or any other provider, you need to have visual voicemail.
In 2017, there are so many things we can use out iPhones for. Some of us use them for shamelessly taking 100s of selfies, some might use it as a tool to navigate and tons of other simply use it as a way to surf the internet. Whatever you use it for, there is no arguing that iPhones are amazing devices that can do a lot.