Related Clues:

• It can be registered
• Viewer ___
• See 46 Across
• Spam, say
• Use the USPS
• Distribute (with "out")
• Vacationer's accumulation, perhaps
• Doorstep delivery
• Letters in a box
• E or G follower
• Unit of land
• Bills, circulars, etc.
• Post office sackful
• Postal delivery, informally
• Weekday delivery