If you are owner of an iPhone, iPod touch, or iPad running iOS 6 then you must be familiar with iMessage app which is Apple’s free MMS-like service. Now many users are facing the problems with iMessage and they are unable to send iMessage from iPhone, iPod touch, or iPad. Some user are facing delays in sending messages while some are completely unable to send messages and getting this “Not Delivered!” report. On the other hand Apple is reporting that there is no issue with iMessage and there is no issue with iMessage.
If you are also facing issues with the iMessage app then you can try disabling and then re-activate the app to fix issues with iMessage app. If this issue is with iMessage app itself or with Apple servers then you have to wait until Apple provides some solution to fix it. Meanwhile you can try this disable the iMessage app by going to the Settings app, scroll down to Messages, tap on it and then tap on iMessage toggle to disable it wait for few minutes and then ON again.