How long can I store my letters and packages?

Essentials plan: 

Letters are stored for free for 30 days and packages free for 60 days. 

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

Enterprise and Virtual Teams plans: 

Letters are stored for free for 60 days and packages free for 60 days. 

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