If someone sends you an MMS in order to share a photo and your phone can't handle the MMS format (either because it's too old or because it's an iPhone), then most carriers will make the image available via the Internet, sending you a text message with access instructions. However, a recent systems upgrade at Optus means that in the future, Optus customers won't have that legacy option: the MMS will simply disappear into the ether. The annoying part? The sender will still get charged for trying to send any pictures, even if they're not received. A workaround if you know the recipient's phone is email-enabled is to send the shot as an attachment, but the whole issue underscores the importance of not just blithely sending out a picture from your phone.