If you don’t know it by now, you might never know. Voicemail greetings are incredibly important to users. It conveys identity, character, and image to callers. In an increasingly digital world, where business is conducted online and over the phone, phone presence is increasingly important. As such, your greeting is a crucial part of the platform. While there are a number of obstacles to be aware of, utilized properly, voicemail greetings can be incredibly helpful and beneficial; therefore, its in users best interest to invest themselves in creating a quality recording.
3.) Welcome to John Doe. Currently we can not answer your call personally, or you are calling us outside of business hours. Please leave us a message with your name and telephone number - we will call you back as soon as possible. Thank you and good bye.

Last but not least a slogan or branding: this is really more important for new customers and people that are calling or leaving a voicemail for the first time rather than returning ones (though it helps a little with them too!). A catchy phrase makes it easier for people to remember your name and recognize you when you give them a call back.
You can play a voice message at different speeds and pause/resume the message, using desktop client visual voicemail, or by dialing into their voicemail. Pressing a certain key on your phone controls how you can hear the voicemail: