mailbag

mail +‎ bag

mailbag (plural mailbags)

1. A strong canvas bag used for the transportation of mail.
   • 1959 December, “New TPOs for the Western Region”, in Trains Illustrated, page 581:

     The communicating doors of adjoining vehicles are opened simultaneously by pressing a large push-button located a suitable height for a man loaded with mailbags to contact it with his shoulder; after a time-lag of seven seconds the doors close automatically.

2. A smaller bag, slung from the shoulders, used for the delivery of mail.
3. (by extension, figurative) The correspondence received by a publishing entity such as a magazine or website.

• mail bag