Pauline McGiffort, age 12, of Nashua, N.H., for her question:

HOW MANY LETTERS GO TO THE DEAD LETTER OFFICE?

Letters and parcels that cannot be delivered or returned to the sender are sent to the dead mail office, a division of the United States Postal Service. About 25 million letters and a million and a half packages end up at the dead mail office every year.

Most large post offices have dead letter offices.

"Dead mail" includes letters and packages that have no return address, mail that is wrongly addressed or poorly wrapped and mail addressed to persons who have moved away and cannot be located.

A sale of the contents of unclaimed parcels is held every three months, adding more than half a million dollars to postal receipts each year.