sìn-siunn信箱

mailbox

mailbox; letter box (private receptacle); post-office box (box in post office station); post box (public collection box)

English Wiktionary, “信箱” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E4%BF%A1%E7%AE%B1 · confidence: Medium (Wiktionary, Hokkien)