‘邮箱’ literally combines ‘邮’ (yóu), meaning ‘mail’ or ‘postal’, and ‘箱’ (xiāng), meaning ‘box’ or ‘container’. Together, it refers to a digital or physical location where messages are received and stored — most commonly used today for an email inbox (e.g., in Gmail or Outlook), though it can also mean a traditional physical mailbox in some contexts. It is a compound noun formed by two morphemes that retain their individual meanings.

The word is widely used in everyday digital communication, tech support, and online account setup. In formal writing or spoken Chinese, ‘邮箱’ almost always means ‘email address’ or ‘email inbox’, not the physical box — that sense is now rare and usually clarified with modifiers like ‘信箱’ (letter box) or ‘邮政邮箱’ (postal mailbox). It appears frequently in registration forms, password recovery prompts, and IT instructions.