With all these things to include, it's easy to write your greeting the wrong way. To keep it simple, something like this:
After helping tens of thousands of companies set up voicemail systems, we’ve learned that there is no set of rules defining what makes a great business voicemail, but there are definitely some key points that you should aim to hit. Before you hit the record button for your voicemail message, take some of these tips into account:

1. Access your digital voice mailbox through your smartphone's touch screen. On an iOS phone, tap on the Phone application and then look for a square in the bottom right hand corner of the screen that reads Voicemail. Tap this button and your voice messages will appear on the screen. Click on any of the messages and press Play to hear the message. On an Android phone, a voicemail icon will appear at the top left of your screen in the Status area if you have an unread voicemail. Swipe your finger down from the top of the screen to view your notifications and then press New Voicemail. Your phone will dial the voice mailbox.
The above section details types of phrasing to avoid; however, it doesn’t detail what users should NOT say on their greeting. Though this is a bit loaded, as there are hundreds of combinations of things one shouldn’t say, there are some key components users should ALWAYS avoid. a. Forget About Slang: You should strive to be as professional and welcoming as possible in your greeting. While this may steer you towards using slang, in an attempt to make callers comfortable, it’ll most likely work against you. As a professional, your demeanor, tone, and speech should be clear cut and well articulated. Using slang undercuts this and works against you. b. Don’t Even Think About Profanity: This is a no-brainer. Never, under any circumstances, curse in your greeting EVER! c. Keep Your Sentences Clean, Don’t Ramble: Introduce yourself and give your caller specific direction. Avoid long diatribes detailing tangent thoughts. Keep it simple and quick. d. Always Return Your Calls: It’s important for callers to feel they are valued. Nothing dissolves this quicker than a greeting that doesn’t stress this. For example, “I’ll call you when I can,” “If I don’t return your call, please call back”—these phrases are terrible and completely destroy any good will you may have with a caller.