The phrase refers to elements contained within an electronic message that serve as hints in a word puzzle. For instance, “attachments” or “carbon copies” might be items found in an email and provide a solution to a crossword prompt.
Deciphering these prompts requires familiarity with email terminology and features. It is a common and often straightforward element of crossword puzzles, appealing to a broad audience with basic computer literacy. Solving such clues can be beneficial in improving vocabulary and problem-solving skills.