Related Clues:

• The first one was sent in 1971
• Letter sent with a click
• Start of Lennon's Imagine reworked, conveying modern message
• Address with an @
• Item in a drafts folder
• What many a meeting could've been
• It might be written on a tablet
• Writing to
• One may be forwarded
• "Inbox zero" hindrance
• It has options for 'cc' and 'bcc'
• Mother during rest returned message
• Message that can be forwarded
• Seems a girl regularly used communication system
• Messages sent without a stamp