Arguably the most intimidating factor when leaving a voice mail is the fact that once you leave the message, "in one take," there is no taking it back. That is why, especially in the business world, an overwhelming amount of people revert to email rather than leaving a voice mail message. Especially in a technologically advanced world, email or text messages are now used as a primary form of communication. Although there is a good argument behind opting for the written word over the spoken one, an email can lack the human touch, the emotion and enthusiasm in a voice, that can often times generate a better response. In fact, there is no impact that compares to delivering a clear, concise, professional message through your own unique human voice.
It's important to mention your follow-up plans in your sales voicemails. Sometimes just the knowledge that you'll call again is enough to entice a prospect to respond. Let them know that if you don't hear back from them, you'll follow up in a few days or next week.

The Serial Position Effect states that the human brain is most adept at recalling the first and last items in a series. For sales reps, this psychological phenomenon means that your voicemails are much more likely to be remembered if they're listened to at the beginning or the end of the day.
The truth is, you can’t delete a voicemail from someone else’s voicemail box once you have recorded it and hung up. So whatever you need to do has to be done BEFORE hanging up. Here’s how you can save yourself from those accidental voicemails that you wish you had never sent in the first place.