Apple's iCloud is apparently having some trouble. A number of users have reported not being able to access Mail starting at 9:30AM EDT today or earlier, leaving them unable to send or receive messages on any device. Some people have said they're able to intermittently access the service, while others have experienced a complete outage. At around 10AM, Apple posted a status update, saying that it was aware of the problem and working to fix it: "Users may be unable to access iCloud mail. Normal service will be restored ASAP. All other services are online and fully operational." This follows another outage yesterday, which Apple reported as resolved.
Apple's services have certainly had outages before, but this is a fairly long time for mail to be down. Apple has estimated that the issue is affecting less than one percent of users — still a pretty big number, though relatively minor in terms of scope. In an odd coincidence, this is happening only a day after a Gmail outage affected a similar proportion of users. If Outlook has any problems tomorrow, we can probably safely assume a nefarious anti-email conspiracy.