updated 08:40 pm EDT, Wed April 18, 2012
Other iCloud services unaffected
[Updated: Full service resumed at 10:30 p.m. PT] Some iCloud users have been affected by mail and notes outages, according to reader reports and status updates from Apple. The problem is said to affect less than one percent of iCloud users, but causes those users to be unable to retrieve e-mail. The problem began around 7 a.m. (Pacific Time) and was partially resolved late in the afternoon, but delays of incoming mail was ongoing until around 10:30 p.m. PT.
The issues began yesterday, with a brief outage of just over half an hour in the afternoon which again affected only a small number of users. Other iCloud services are said to be unaffected by the issue.
Apart from some initial teething issues, Apple's iCloud service has had a generally smoother rollout than the more-troubled MobileMe launch of 2008, which was afflicted with more widespread service problems. Partially as a result of that launch, Apple revamped the way it reports outages and briefly launched a blog. The current page gives details on when problems occur, but of course does not offer estimates on when service will be restored. It also only lists the most recent disruptions rather than a full history.
There have been reports that the iCloud web client is unaffected by the issue, so users can try a web browser to check mail if they are among those affected by the outage. Quick checks with various regional correspondents indicates that the current problem is limited in scope.
Updated message from 6:15 p.m. PDT