Typically, a good business voicemail greeting should comprise the following elements: A warm greeting. Your name, the name of your company and department name. Make an apology for being unable to take the call. Ask the caller to leave a message. Let the caller know when to expect a return call.
I’d also say that it might be helpful for this sales agent to be using a script to leave a message. Most of the time when I listen to voice mail, I don’t have a lot of time. Messages that sound like the sales person is fumbling for words make it very frustrating for the message recipient.

You may think your voicemail message is professional. But when you listen back it could sound rushed or shaky. Listen to it regularly to see if changes are needed.
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.