After creating, the Voicemail Greeting, you can test it by calling to your number from another phone, and see if it is playing correctly or not. Open the Phone App. On the lower screen, tap on the Voicemail option. Select Custom, with this option, you can record the personal voicemail greeting on the iPhone. Tap Record, to start recording the voicemail greeting message on the iPhone. Greeting samples are given in this article below, Once you are done with recording, tap Play to listen. Lastly, if everything is alright, and custom voicemail recording is perfect, then tap Save.
Scroll down to the “Greetings” section and click the speaker icon (manage) next to Voicemail Greeting. Click Add Greeting. Select the Record radio button. Enter the number or extension of the phone you wish to record the greeting on. Name the greeting. Click Call and follow the instructions given to you on the phone.

I got a new cell phone recently. As the world stood in line to pick up the latest iPhone 8, I graduated to the 6S. I pride myself on that actually. As with all new phones in the 21st century, the voicemail must be set up anew. I used the default message for the first few days, but finally settled down to record a more personal greeting.
I am not a voice talent, and I hate the sound of my own voice. Every time I lose my cell phone (daily), I call it from another line to help myself find it. And every time I do this, I wish my voicemail message sounded…different. I’m always reminded that I should sit down and rerecord it, so it makes a more professional first impression.