Keep it Brief. Time is money in business, so if your voicemail is long, chances are the caller will simply disengage before the cue to leave a message even sounds. Keep your voicemail short. The most should be around 30 seconds, and even that’s pressing it. We’ve grown into a country where our attention span can last only about 10 seconds in some cases, so keep it short, brief and to the point. Persuade and Engage the Caller. If someone calls your business, they already have an intention. It’s the quality of your voicemail that plays a factor if they consider you a company they’d like to deal with. This is your chance to motivate someone to engage in a meaningful conversation with you. If your voicemail is shoddy, chances are they’ll hang up, or lose motivation to continue the call. In other words, your voice mail must engage and entice someone to the point that they care enough to leave you a message.
A custom phone greeting is a recording that plays automatically when a customer calls. They can be set to play right at the start as a professional welcome, as a voicemail greeting, or even as an away message when you can’t answer. Business phone greetings can give your small business a larger and more professional appearance.

Hello, you have reached the office of Doctor X. I’m on call at the moment, so I’m unable to respond to your call immediately. Please leave your name, reason for calling, and your number and I will return your call as soon as possible, or call my secretary at Y.
In Microsoft 365, you can record a greeting, edit call answering rules, set up Outlook Voice Access, edit text message and email notification settings, and turn on voice mail preview using Outlook on the web.