Placing it in your home mailbox and raising the red flag to alert your carrier.
Choose appropriate paper to match your purpose—professional-grade for formal mail or decorative for friends.
Clearly write the recipient's full name, street address (including apartment or suite number), city, state, and ZIP code in the middle of the envelope.
If your letter is heavier than 1 ounce, rigid, or lumpy (containing items like coins), it may require a non-machinable surcharge or additional stamps.