Professional business voicemail greetings are significantly different from ones you record for individual use and complete your professional business image. They’re more generic in nature and designed to provide information to the caller while ensuring they leave a message. Where possible, explain when you expect to return calls. Typically, they’re recorded for the following:
Some phone systems allow employees to specify a primary greeting and set secondary messages to cover absences or vacations. When creating an individual voicemail greeting, clearly identify yourself, your role, and your company, and let the caller know when you will be able to return their call.

"You're growing tired. Your eyelids are getting heavy. You feel very sleepy now. You are gradually losing your willpower and your ability to resist suggestions. When you hear the tone you will feel helplessly compelled to leave your name, number, and a message."
I have a confession to make: I haven't recorded a new voicemail greeting in nearly a decade. Since then, I've (hopefully) become more articulate, poised, and self-assured. But hear my voicemail recording, and you'd think I was still new to the work world, a little unsure of myself — and probably not an authority.