A bizarre glitch has revealed the existence of "pre-filtering" spam deletion algorithms being used by Apple for its iCloud email. The company acknowledged the issue and has since fixed it, but when an iCloud user would attempt to send an email with the phrase "barely legal teens" in the subject, body or title of some kinds of attachments to another iCloud user, the email would not be delivered. Replies to emails with the phrase, or messages sent to non-iCloud users with the phrase, were successfully sent. Unusually, offending messages were deleted rather than simply flagged as spam.
