A voice message saved on your voicemail is stranded within that application (AFAICT). Some cell carriers allow forwarding of voicemails or have an app for that. There are also some apps for replacing voicemail, but may not work on all carriers. That's all I've gleaned from the web....
Since you've already recorded the voicemail and merely want to send it to someone, you might just play it back over the iPhone (speakerphone or headphone jack) and record the message with a PC/Mac, then email or text it out. This is the dirty way, but easy.
Here's an example of how to do it:
Message was edited by: seeblue1
My apologies for the delayed response. If you are referring to a voice memo you can send it to someone by clicking on the memo then hit 'share'. You will have the option to send as message or email. If you received a voice message by text, you can forward it by clicking edit at the top right and then click the message that you would like to forward...then select forward at the bottom right.
For voicemail, you may have to download an app from the app store to forward because that function is not built into the operating system.