Google is discontinuing yet another feature and this time it is the messaging feature within YouTube. According to the notice that now shows up within the app when you go to your inbox, the feature will be discontinued on September 18. Clicking on the Learn More button provides more information on the subject, including the information that some features such as sending videos as messages may become unavailable even before September 18. Warning message now seen in the app Google has instructions on how to download a copy of your messages on the support page, linked below....