A relatively unprofessional one — like mine, for instance — does the opposite: It encourages prospects, recruiters, and potential connections to run in the other direction.
While there are endless ways you could say hello in a custom voicemail greeting, there are a few main generic lines that most of us have probably heard many times. Hello, you have reached the voicemail of (person of company) we are unable to get to the phone at the moment, please leave your name and number, and we will be happy to call you back soon. Thank you. Thank you for calling (company or person) we are not available or are on the other line with another customer, please hold and a representative will be with you shortly. Thank you for calling (company) if you know the extension of the person you are trying to reach dial it now, for billing press 1, for customer service press 2. or press 0 for the operator. Each professional custom voicemail is unique to the person or the company and can be structured any way you need it to represent your brand, business, or you as a person. There are options such as adding music that also make the voicemail greeting attractive. These are all ideas that we can work on in the free consultation I offer on all projects. It is best if you have the script on a word doc or notepad, and if you need help refining, I can help there also.

Record your greeting. Under Voice mail, select Greetings. Select the type of greeting you want to record. Select Call me to play or record the selected greeting. Enter your phone number and select Dial. Follow the instructions in the recorded message to record your greeting. When finished recording, click Save.
Tap on Voicemail; From there, you can turn Voicemail on or off, set your Greeting as a default (or record a custom greeting), and turn Voicemail Transcription on or off. Record your own voicemail greeting. Note: Recording a custom voicemail greeting is only available through our iOS or Android app versions.