Remember, your prospects (and you too, if you're honest) care mainly about themselves. In other words, your sales voicemails will be much more successful if the benefit to the prospect is clearly stated.
If someone takes the time to call and leave you a voice message, they usually have a reason that they are calling. It does convey a certain level of interest when someone is willing to hop on the phone with you. If they were less interested, they would probably send you an email or fill out a form on your website.

Answer (1 of 5): You do it by simple, direct, declarative sentences, devoid of exaggeration. Every week, I receive perhaps 6 or 7 email queries from people who seek to do business, with me, but who are most unskilled in my native language: English. I …
No emoji or smiley face anything in professional emails. Sad, but true. {I wish I could insert a sad emoji right here.} Keep everything clear and concise. Write an email like you value the other person’s time. Get to the point. Of course, you still want to communicate effectively, but no need to write a dissertation on the subject.