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.
The first time you access your mailbox, the system will walk you through setting up your password, name recordings, and greetings. Please follow this all the way through and it will not play the tutorial again. The following instructions are for when you need to change something after the initial setup.

This video on English Voicemail Greeting Sample covers the key areas of English pronunciation such as double / diphthong vowels, long vowels, word stress and word endings and more.
You should also research other people in the prospect’s organization. Selecting the right people, such as the prospect’s manager or department head, facilitates the ability to build rapport and adds a sense of urgency when you mention them in the voicemail.