You receive 30 days free storage for all letters, magazines, letter packs, and small to medium-size packages.
Packages that exceed 1,728 cubic inches (equivalent to 12 inches x 12 inches x 12 inches) are given 10 days free storage.
Packages that exceed 4,895 cubic inches (equivalent to 24 inches x 17 inches x 12 inches) are given 5 days free storage.
Once free storage days are exceeded, letters and flat mail are charged $1.10 per item per month, and packages are charged $1.10 per pound per month (higher of actual or dimensional weight). To avoid storage charges, recycle, shred, forward, or pick up mail items.