Friends and colleagues speak to each using first names only. So do people of authority. They do not call each other and leave voicemail messages asking for Mister, Miss, or Mrs. Therefore, when you call a person you want to do business with and you leave a voicemail message, refer to them by their first name only. Don't say mister, miss, or misses. Don't say their last name. Begin your voicemail message by saying only "hi/hello" followed by the person's first name. Or, you can even forget the "hi/hello" and just say the person's first name. That is how you show confidence and authority and separate yourself from weak salespeople.
Your voicemail greeting is the first introduction to your office — what kind of impression do you want to leave?

“I’m answering this phone for my friend who tells me it’s your nature to hang up and not leave a message, but I should remind you that nature is what we are put on this earth to rise above. So please, leave a message at the sound of the beep… for the sake of anthropology.”
-Hello. All of our operators are busy right now, but if you’ll leave your name, telephone number, a brief message, and the time you called, we’ll get back to you as soon as possible. Thank you and have a pleasant day.