Related Clues:

• College bookstore stock
• Spammer's medium
• Write without pen or pencil
• Online memo
• Place for an emoticon
• Call alternative
• Cyberspace note
• Correspondence sans stamp
• College student's purchases
• It doesn't leave a paper trail?
• Virtual inbox fill
• It may come with attachments
• Target of some filters
• Sends a message, nowadays
• Forward, perhaps