Related Clues:

• 'You've got mail!' letters
• Letters that don't need stamps
• Contact, in a way
• Screen writing?
• MSN alternative
• Virus carrier, sometimes
• Net letters
• It may be filtered
• Phone displacer
• Yahoo offering
• One way to the WWW
• Letters that can't be found at the post office
• Trio after @, perhaps
• It's sent with a click
• Quick correspondence