Apparently, if you are a top Postal Service executive who wants a big raise, the way to get it is to resign. The strategy has worked for some, according to a report by the agency’s inspector general. Former Postal Service employees have been awarded more than 2,700 outside services contracts by the agency since 1991, according to the report. Between 2006 and 2009, 17 former executives were given no-bid contracts. Most of them received six-figure payments. One was given a $260,000 contract to train his successor.