This article is your complete guide to resetting the voicemail password on an iPhone. Know how to secure your voicemail inbox, with periodic password changes.
A formal voicemail greeting is one with a professional tone. It could be for a business or for personal reasons. Formal voicemail greetings are designed to impart a sense of authenticity. They leave the caller with a sense of trust in your abilities, whatever they may be.

“Hi there. This is (name) speaking. I’m home right now, and in a moment, I’ll have a decision to make. Leave your name and number, and I’ll be thinking about it…”
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.