Home / HSK Vocabulary / HSK 5 / 信箱 信箱 xìn xiāng HSK 5 · C1 Meanings mailbox post office box Quick facts HSK LevelHSK 5 CEFRC1 ← Back to HSK 5 word list Practice 信箱 with flashcards MandoBridge uses spaced repetition to help you remember HSK 5 vocabulary — free on iOS and Android.