From Longman Dictionary of Contemporary Englishpostbagpost‧bag /ˈpəʊstbæɡ $ ˈpoʊst-/ noun British English 1 [singular]TCMLETTER all the letters received by an important person, television programme etc on a particular occasion We’ve had an enormous postbag on the recent programme changes.2 [countable]TCM a bag for carrying letters, used by the person who delivers them SYN mailbag American English
Examples from the Corpus
postbag• The winners will be drawn from a postbag of correct entries on 22 January 1993.• We expected a big postbag but nothing could have prepared us for the fantastic response we received!• I was mildly worried by the large postbag.• There are strong feelings on both sides, as my postbag bears witness.• We have two more copies to give away, drawing from our postbag after Wednesday's final post.• We have six to give away to the first names drawn from the postbag on 7 March.• The first five names out of the postbag after that date will win a make-over.• The first 200 correct winners out of the postbag on Monday, September 14 will receive prizes.From Longman Business Dictionarypostbagpost‧bag /ˈpəʊstbægˈpoʊst-/ noun [singular] British English all the letters received by a public person, television programme etcThe series did not please everyone, and the TV network’s postbag was full of complaints. 