The phrase refers to instances where clues or answers in crossword puzzles relate to electronic mail identifiers. This can include direct references to the format of an internet communication location or related concepts such as domains, “@” symbols, or specific mail services. For instance, a clue might be “Internet communication identifier” with the answer being “EMAILADDRESS.”
The prevalence of such crossword entries reflects the ubiquity and cultural significance of digital correspondence in modern society. Solving these clues relies on general knowledge and familiarity with internet conventions. It also indirectly reinforces public awareness of the structure and terminology associated with online communication.