Simply speak into your phone or computer while recording a greeting with your business phone service. If you need to create your own audio file, the voice memo app on your phone should do fine.
With Optimum Business, you get a feature-rich package that has everything you need in a small business phone service. We’re all about connecting you with your customers, whether you need just one line or all the hardware to fill an entire office.

Company Description: Nextiva is a large virtual phone service provider and a well-known brand within the industry. They allow companies to register toll-free 1-800 numbers or local numbers anywhere in the U.S. Their setup for their service is instantaneous — once you pay, you’ll be able to begin using Nextiva right away. Their features include the ability to use their service on a mobile device and manage your calls online from anywhere in the world.
I’m actively researching phone services for our company, and I agree with some of the others. This is an overview more than a review, doesn’t go in-depth enuff. But, it’s a good start for me, I did find it helpful, weblinks are easily accessible. Just not as informative as I’d expected and hoped.