Forget about messing around with apps. There’s a powerful voicemail handling system built into nearly every big carrier today — and that system almost always includes a system for recording a voice message and sending it directly without ringing the target phone. I will walk you through the process of doing this on Straight Talk (since that happens to be my carrier) but most carriers will have similar systems.
Below are examples of what to say in a voicemail message. Whether recording the message for a personal phone or a business line, these ideas will help. Using humor is appropriate in some situations, but humor should be avoided in situations including serious businesses where reputations could be damaged or people could become upset.

You’ve reached [LinkedPhone – Where Freedom Rings]. We are currently off-duty. Our business hours are [Monday through Saturday, 9am to 7pm Eastern Standard Time]. Please leave your name, number, and the reason for your call and we’ll get back to you on the next business day. Thank you.
You can’t always get to the phone when clients, partners, investors, or colleagues call you. When this happens, a professional voicemail greeting helps you make a positive impression and tells them what to do next. There are a variety of ways to convey your message. If you’re not sure what type of message to record for your own voicemail box, here’s a definitive guide to get you started.