When iCloud was introduced, Apple made the announcement that MobileMe, the predecessor to iCloud, would shut down on June 30th of 2012. MobileMe subscribers had plenty of advance warning to move their stuff off the service before deletion.
Well, Apple has now sending out 30-day warning emails reminding MobileMe subscribers of the shutdown. The email notifies customers that they must move to iCloud in order for their email to continue working, while also offering instructions on transitioning over to the new online offering.
Customers who have already moved over to iCloud are reminded to move their Gallery photos, iDisk files, and iWeb sites before the shutdown. So, download all of your stuff, and find a new home for it.