The best text-to-speech voices don't sound robotic at all. Do a "text to speech" search in Google to explore your options. Type in your script and presto! You'll get an instant greeting with a natural sounding voice. You can select from a broad spectrum of male & female voices with any local or foreign accent you choose. LinkedPhone offers text-to-speech built right into our software. It's super popular and our users love it!
“Hi, you’ve reached [your name] at [your company]. I’m unavailable right now — probably helping [type of company] get [X results, e.g. ‘double their leads in 60 days,’ ‘hire the best and brightest engineers,’ ‘convert 40% more customers.’] Leave your name and number, and we’ll discuss how your company can see similar results.” “Hello, this is [your name] at [company]. Thanks for calling. Please leave your name, number, and reason you’d like to chat, and I’ll get to back to you ASAP.” “Hi, you’ve reached [name] at [company]. If you need a quick response, please shoot me an email at [insert email address] and I’ll be in touch by EOD tomorrow. If it’s not urgent, leave me a message with your name and number. Have a great day.” “Hey, this is [your name]. If you’re calling for [X reason], please [contact so-and-so] or [go to our website, send me an email]. For all other inquiries, leave your name and a brief message and I’ll call you back within [one, two, three] business day[s].” “Hello, you’ve reached [name] at company. I’m unable to come to the phone right now. Leave your name and number, and I’ll return your call as soon as I’m free. Thank you.”

A professional voicemail should be short and succinct. Simply introduce your company, ask the caller to leave their information, and let the caller know when to expect a callback. Once you record your greeting, you can easily upload it into the OpenPhone app. Simply go to your phone number’s settings, then choose to record a greeting, upload an mp3 file, or use text-to-speech.
No45: Hello, this is Jim. Unfortunately I can't answer the phone right now because I've just come back from the Mirror Worlds and I'm still made up of antimatter, so if I were to pick up the phone right now, the resulting energy release would make Hiroshima look like a wet firecracker. So leave a message at the tone and I'll get back to you as soon as my component particles have been restored to their normal charges.