Last month, it was reported that a bug had been discovered that caused some recent iOS devices to be bricked if the user changed the date to January 1, 1970. It now appears that the function related to this problem, Unix Time, is also responsible for a slew of ghostly emails received by users that are dated from 1969 and 1970.
The anomaly has apparently been around since 2010 but seems to have gained more exposure recently, possibly in light of the bricking bug. Unlike that self-inflicted problem, which Apple will be fixing in its iOS 9.3 update, the emails aren't malicious and won't damage a device.
The glitch has resulted in the emails, which have no content, subject line, or sender, being sent to iPhones and iPads. Some of the messages are dated from December 31, 1969, and others from January 1, 1970. Users have found that they can't interact with the emails, so there's no way to delete them.
Like the bricking problem, these ghost emails are related to the Unix, or Epoch, time - a reference point that devices count away from so they can work out the date. January 1, 1970, represents 0 in Unix time, and the current Unix Timestamp is around 1.45 billion - the number of seconds that have passed since point zero.
The issue often appears when there is a problem between the mail servers and a few email clients, including the iOS mail app and Microsoft's Outlook iOS app, and is usually due to users travelling between different time zones. When an email can't read the time data, the iPhone will default to zero - 1970. Some users in the Western Hemisphere see dates of December 31, 1969 due to timezone differences.
The issue can be fixed by simply closing down the app and performing a hard reset of the device. Once this is done, the emails should be gone.