Voicemail messages left on your mobile are automatically saved in your Visual Voicemail. If you wish to delete a voicemail message, simply tap the Delete button. The message will be placed in the Deleted Messages folder, but will not be deleted from your voicemail (you can restore these messages later). To permanently delete messages, go to the Deleted Messages folder and select Clear All.
You can create a custom voicemail greeting on your iPhone 5 that is in your voice, and says exactly what you want it to say. So continue reading below to learn how to record a voicemail greeting on your iPhone and set it to play on any call that goes to voicemail.

If you use voice mail or an answering machine to answer calls when you can't, make sure that you have a professional message recorded, that does the same thing as tip #3, and gives callers any other pertinent information before it records their messages. Update your voice mail message as needed.
From the Skype for Business desktop app (if you are running Click-2-Run build C2R 8201.1002 or later), select Set Up Voice Mail. Change your Call Answering Rules You can change what options your callers have when they reach the voicemail service; get disconnected, hear your greeting, record a message, choose to be transferred to the number or user you select. Change your prompt language This is the prompt language that is played to callers. For list of supported languages, see Languages for voicemail greetings and messages from Skype for Business. Configure your Out of Office greeting This is the customized greeting message that is played to callers when your status is Out of Office. This option can be activated "Always," when you have an active "Auto Reply" in Outlook, or whenever you have an out-of-office calendar appointment.  Where you can get your voicemail messages from