Related Clues:

• Interoffice missive
• Cubicle-to-cubicle note
• Postal alternative
• Something you click to open
• Deliver spam
• Send, on a computer
• Cyber-missive
• It might have an attachment
• Inbox contents
• Note to self
• Hit "Send"
• Inbox buildup
• It's often filtered
• Office info
• Modern means of relaying jokes