Before any postal worker touches an envelope, high-speed sorting apparatuses run the show. The United States Postal Service relies on an advanced envelope optical character reader (OCR) integrated directly into automated mail processing machines. These camera systems photograph each envelope, convert handwritten or printed text into digital data, cross-reference that data against the National Customer Support Center database, and spray an invisible fluorescent or visible 11-digit Intelligent Mail barcode along the bottom edge.
The sorting machine reads text from bottom to top, scanning the country and state line first, then the street details, and finally the recipient's name. If an ink smudge obscures the city or a non-standard font confuses the scanner, the optical reader aborts. The piece drops into a reject stacker for manual keying or ends up back at the distribution center. Maintaining clean margins, stark contrast, and standard line breaks is not about aesthetic preference; it directly preserves machine readability.
