How long can I store my letters and packages?

Basic plan: 

Letters are stored for free for 45 days and packages free for 30 days. 

After that storage fees apply at: $0.05/letter/day; $0.10/lb/box/day

Plus plan: 

Letters are stored for free for 90 days and packages free for 30 days. 

After that storage fees apply at: $0.05/letter/day; $0.10/lb/box/day

Business plan: 

Letters are stored for free for 180 days and packages free for 90 days. 

After that storage fees apply at: $0.05/letter/day; $0.10/lb/box/day