When mail-sorting machines around the country encounter addresses they cannot read, an electronic image of the bad handwriting or faded address is transmitted to operators here who view them and try to fill in the missing information by typing in a letter or a number. Once corrected, the information is returned to the processing plant where the mail is sent on to a local post office, ultimately ending up where it is supposed to go.

“We get the worst of the worst,” Ms. Batin said. “It used to be that we’d get letters that were somewhat legible but the machines weren’t good enough to read them. Now we get letters and packages with the most awful handwriting you can imagine. Still, it’s our job to make sure it gets to where it’s supposed to go.”

Over the years, the Postal Service has become the world leader in optical character recognition — software capable of reading computer-generated lettering and handwriting — sinking millions of dollars into equipment that can read nearly 98 percent of all hand-addressed mail and 99.5 percent of machine-addressed pieces.

That was not always the case.