This is optional, but you can also leave another form of contact on your voicemail, like an email, that the employer who is calling can utilize. This will show that you want to get back to them as quickly as possible, and you are giving them multiple ways to do so. This isn’t necessary, but can be a good step if you want to squeeze a little more into the voicemail without going overboard.
Don't lose customers after hours. Here are some best practices and sample scripts for professional auto attendant and voicemail phone greetings.

Hello, you are talking to a machine. I am capable of receiving messages. My owners do not need siding, windows, or a hot tub, and their carpets are clean. They give to charity at the office and don't need their picture taken. If you're still with me, leave your name and home phone number and they will get back to you.
Once you thank your customers for calling, state your name and the department. Make sure to speak clearly so the caller knows they called the right place and can understand what is being said. Don’t rush through in case the caller wants to write the information down.