1. Mail that includes letters and postcards and packages sealed against inspection
   - first class, first-class mail, 1st-class mail

Type of: mail

• genus Polybotrya
• genus Polycirrus
• genus Polydactylus
• genus Polyergus
• genus Polygala
• genus Polygonatum
• genus Polygonia
• genus Polygonum
• genus Polyodon
• genus Polypedates
• genus Polypodium
• genus Polyporus
• genus Polyprion
• genus Polystichum
• genus Pomacanthus
• genus Pomacentrus
• genus Pomaderris
• genus Pomatomus
• genus Pomolobus
• genus Pomoxis
• genus Poncirus
• genus Pongamia
• genus Pongo
• genus Pontederia
• genus Pooecetes