From any Home screen, tap Applications.Scroll to and tap Visual Voicemail.Tap Greetings.Tap the greeting you want to use or tap Record a new greeting. To delete messages in bulk, select the menu bar in the top-right corner (represented by three vertical dots). Choose “Edit” and tap each individual voicemail that you wish to delete. The screen also includes a bulk select application for bulk deletion.
4 hours agoThe process is very simple. You'll just have to click the green phone icon, the same place you make calls, and navigate to the voicemail screen. On the voicemail screen, you'll see a greetings option on the top left. Once you click greeting, you can change it from default to custom and record your custom greeting.

If you don’t make any changes the default iPhone voicemail message is pretty bland and not very professional. It is a good idea to change the iPhone voicemail message to something more professional or at least something that lets callers know they reached the right person.
Tap Record a new greeting. Note: If necessary, delete an existing greeting (limit of 2 greetings) to make room for the new greeting: Tap the Menu key, tap Delete greetings, tap the check box next to the desired greeting, and then tap Delete.