| Service | Delivery Window | Features |
|---|---|---|
| Priority Mail Express | 1–2 business days (guaranteed by 6 PM) | Tracking, $100 insurance, signature optional |
| Priority Mail | 2–3 business days | Tracking, $100 insurance, free boxes |
| First-Class Mail (letters/flats ≤13 oz) | 2–5 business days | No tracking (letters), economical |
| USPS Ground Advantage | 2–5 business days | Packages up to 70 lbs, tracking |
Always use tracking for valuable/time-sensitive items. USPS Informed Delivery (free) shows scanned mail images daily.