Related Clues:

• Postmarked pieces
• Push the envelope?
• Post office delivery
• It's sometimes certified
• Garb for Galahad
• Junk in the box?
• Kind of bag or box
• Hard-to-break plates
• Small package
• Snail ___
• It may contain a lot of letters
• FedEx arrival
• There's a lot of junk in it
• Four letters?
• Blue box material