/ ˈpəʊstbæg; NAmE ˈpoʊst-/ noun ( BrE )
1.
(also mail·bag NAmE , BrE ) [ usually sing. ] all the letters, emails, etc. received by a newspaper, a TV station, a website, or an important person at a particular time or about a particular subject :
We had a huge postbag on the subject from our readers.
2.
= mailbag (1)