VirtualPBX provides not just a virtual voicemail system for business, but also a full suite of phone communication features. From a personalized greeting that welcomes anyone who calls their business, to the ability to transfer calls to another phone or person mid-conversation, clients of VirtualPBX get the kind of benefits that would cost hundreds or thousands to replicate in personal hardware.
Last but not least, we provide an easy way to keep track of the conversations you and your team have with customers. We call it Client Notes. Client Notes help your business effortlessly keep track of conversations, to-do’s and reminders so that everyone on your team is on the same page when dealing with a specific client. It’s a high-value customer relationship management tool (CRM) that everyone loves.

SIP is what's used for the vast majority of modern VoIP phone systems. It also handles phone service, video conferencing, and several other tasks just fine, which is why its use is so widespread. Where it has trouble is data security, but more on that in a bit.
You don’t have to spell out every single thing that you think they might want to know. Have some faith that your callers will be able to figure things out on their own. Be natural but informative.