Taking it directly to a Post Office counter, which is recommended if you need proof of mailing (Certified Mail) or aren't sure of the required postage. How to Mail a Letter | National Postal Museum
Standard letters include a formal or casual salutation, the body of the message, a polite closing (e.g., "Sincerely" or "Best"), and your signature. 2. Address the Envelope MAIL A LETTER
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. Taking it directly to a Post Office counter,
Use a ballpoint pen with dark ink and avoid writing across seams or tape. 3. Apply Correct Postage the body of the message