An update posted to Apple's after 3 p.m. PT Tuesday confirmed that some users "may be unable to access iCloud mail." The outage affected around 1.1 percent of subscribers according to Apple, which promised to restore services as soon as possible. Another update was promised by 5 p.m. PT.

That's likely to be of small comfort to the users affected by the outage, many of whom took to Twitter to . Some users reported that mail had been unavailable since early Tuesday morning.

The outage seemed to affect users randomly. One staffer's father reported being without mail since 7 a.m. PT Tuesday, while his mother had no interruption in service.

An Apple spokesperson declined to comment further on the outage, referring to the company's system status update.

The iCloud outage comes a day before Apple holds a in San Francisco, where the company is expected to introduce a new iPhone.