d. Utilizing Ambiguity Over Clarity: When setting up your voicemail greeting be direct and to the point. Tell callers your information, a brief greeting, and direction—i.e. “Hi, this is Jim Shamalam (from Iron Industries). Sorry I can’t take your call right now. Please leave your name number, and a brief message and I’ll get back to you as soon as possible. Thank you.” This is ideal, as you inform callers and let them know what they should do to ensure a return call. A lack of direction can lead to callers leaving incomplete messages (lacking contact or other information) or even callers hanging up without leaving a message altogether.
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.

Using the services of a professional actor with experience in phone system recordings helps ensure truly professional-sounding voicemail greetings for a business. Professional actors backed by experienced audio directors and studio-grade recording equipment can produce high-quality recordings for phone system messages such as voicemail greetings.
Solution: Poor sound quality is unlikely the fault of a reliable business voicemail service that uses VoIP technology, Baldwin says. So garbled voicemails are often due to callers’ poor mobile phone reception while leaving their message—and you may just need to call them back, assuming you can figure out their phone number. But if the problem does seem to be your voicemail, make sure you’re using a business phone and voicemail service that uses VoIP and not relying on, say, your mobile phone’s voice mailbox.