Probably this will be the handiest website for you to bookmark! Jim Hamm strongly suggests, "Here's a site published by Apple that will alert you to a known problem with a particular Apple System.
"Let's say, for example, you're having a problem with iCloud Mail. Is it your computer, or ? A quick check of this site will alert you if it is a known problem that may be system-wide. If there's no alert showing, then take a closer look at your computer."
He closes with this, "You might want to bookmark this site -- it could be helpful." But as soon as you view that site you WILL see its usefulness.