Mailing a letter seems like a simple task. Most people give little thought to dropping their mail into an official blue mail box or other mail receptacle. During my years of employment with the United States Postal Service, I heard almost every customer complaint and criticism imaginable. Sometimes the problem was the fault of the postal service but sometimes the problem could be traced right back to the customer.
One of the most common complaints I heard was that a customer’s mail was not being delivered to its destination in a timely manner. Sometimes customers would complain that a greeting card or a bill payment arrived late, even though it had been mailed on time. In my experience, there was one frequent cause of that problem.
Since every address on every piece of mail is read and processed by OCR’s (optical character readers), the legibility of the address must be reasonably precise. If a machine misreads a number in the zip code, the corresponding delivery bar code sprayed on the letter will also be incorrect. An incorrect bar code on a letter could send a letter to Maine instead of California.
When addressing envelopes, people don’t always write neatly. Sloppy or overly-embellished handwriting, or odd curly-cues on numbers, easily trip up the optical character readers that process the mail. Even though the machines can interpret all kinds of handwriting and print, they will often misread characters that are not clearly written.
For example, pretend you live in San Diego, California. You are in a hurry when you address a birthday card to your sister in Fremont, California – Zip Code 94537. You scribble a sloppy 94537 and drop the card into a mail box. The next stop for your card is an automated mail processing facility.
The optical zip code reader may interpret your sloppy 9 as a zero. The machine would bar code your letter to go to Boothbay, Maine – Zip Code 04537, on the other side of the country. Your card travels to Maine, going in the complete opposite direction from where you intended. Before automated mail processing, a mail clerk would most likely have caught the error and hand-corrected it before the mail piece ever left the original post office but things don’t work like that with mass automation.
The birthday card will arrive within two or three days at the post office in Boothbay, Maine. A mail clerk there will realize that it has been misdirected. The clerk will then take your mail piece and attempt to mask the incorrect bar code and the scribbled zip code with a black marker. All errant letters are then sent out in the regular afternoon mail dispatch for reprocessing in a large mail facility.
Sometimes a letter with a wrong bar code will slip into the postal netherworld known as loop mail. It might circulate back to the wrong post office a second or third time. This can happen if the bar code is not completely marked out and the bar code scanner continues to read the incorrect bar code each time the mail piece passes through a processing facility. The intent of the post office is that a letter NEVER get caught in “loop mail” hell, because it makes customers mad and makes the postal service look inefficient.
By the time a letter travels around even once in the wrong direction, it has usually missed the intended delivery date. Most first class mail takes at least two to three days to makes its journey, depending on the distance, so a misdirected letter can arrive at the proper address considerably later than you intended, if there’s even a slight problem. If you’ve ever had a letter or card take a week or two longer to arrive than it should have, it may have been caught in loop mail.
Next time you mail a card or letter, it wouldn’t hurt to double-check your handwriting. Make sure that you write as neatly as possible and try to clearly print all numbers. You’ll be doing yourself a favor and maybe your letters will never end up in loop mail.