the fixed system message, "I'm sorry, the person you are calling is currently on the phone." followed by the fixed system prompt, "Begin speaking after the tone, then hang-up when you are finished or press any key for further options."
If it works better for you, offer your callers the option to email you, or even send over a text to a VoIP texting app, or even your personal number if you don’t mind. Many people will prefer the ability to quickly text or email, and callers will appreciate the increased level of service.

When you create a professional voicemail greeting, it can be a good idea to think about what your callers might want to know. After doing so, you can make a list of points to cover in your voice message; it might also be a good idea to write out the entire greeting on a piece of paper. The ideal message should be somewhere between 10 and 20 seconds, so you may want to time yourself repeating your message before you record it. After composing your telephone message, it can be a good idea to get a second opinion of this greeting so you can make sure it sounds professional. Writing down a voicemail greeting helps prevent mistakes when recording it.
15. “Hello, you’ve reached the Sales Department at [Company name]. All of our representatives are currently helping clients [insert goal such as, ‘achieve 40% growth through streamlining HR’] and are unable to take your call. Instead of putting you on hold and taking up your valuable time, please leave your name, company, and phone number and we’ll give you a call back ASAP. Thank you!”