Related Clues:

• It may be junk
• It often contains lots of letters
• It might be four letters
• "You've got __"
• Vacationer's accumulation
• FedEx delivery
• Drop in a letter box
• Postal deliveries
• Letters and such
• Drop in a letterbox
• Letters, collectively
• Real estate chunk
• Drop in a slot
• Stuff in a box on the street
• It's not delivered on Sundays