Because they're working across such a broad array of features and channels, many of today's phone systems are adopting the moniker of Unified Communications-as-a-Service (UCaaS). These are generally cloud-based, virtual PBXes (private branch exchanges) that include at least one (usually multiple) software clients to enhance their functionality on the web, desktop, and especially mobile devices. Even residential VoIP systems come with features that are simply impossible with a conventional telephone system.
Most VoIP solutions will require stable and consistent internet connectivity at all your office locations where VoIP will be used. At the very least, your business phone system must have access to a business-class internet link, so discuss these needs with your company's internet service provider (ISP). This should be a dedicated link through a dedicated router if you expect your phone calls to sound as if they were coming from a business and not someone's home Skype connection. At a minimum, it's important to have a router that can create virtual LANs (VLANs) and also has the ability to encrypt your voice traffic. These days, you need end-to-end VoIP security for any call.

A voicemail greeting is a simple message that plays before callers leave a message. It may play either when you don’t answer or if your phone is off. A professional greeting may encourage people to leave messages, which in turn makes it easier for you to get back in touch. Keeping that communication open and efficient may lead to better business relationships. It also helps you put forth a professional image for your business.
If you’re planning on doing a sales call sprint via phone – so, possibly via voicemail – trust the scripts crafted by close.io’s Steli Efti on this one . Finally, since it tends to come out of people nearly automatically whenever they leave VMs on phones: Please don’t say …