Sending a Voice Message and not a Call?

[CandyIowa]

Hi,
I don't even know if this is possible on my iPhone 3Gs, but if it is, can someone please tell me how to do it?
I received a voice message yesterday. My phone was not busy, and I don't recall hearing it ring. The person should have been able to call through.
How can we send a voice message to another person's phone?
Thanks.
Candy

 

[jomckillop]

Maybe your phone went out of signal