mBx

MBX is an acronym that appears in multiple, largely unrelated contexts, and there is no single universal definition for the term. In computing, MBX is commonly seen as shorthand for a mailbox or message box. In email and messaging workflows, it can refer to storage locations, file containers, or directory names used by various clients and servers. The exact structure and content of MBX-based storage vary by product, and MBX storage formats are distinct from the more widely known mbox format.

Beyond mailbox usage, MBX is also used as the name or abbreviation for several software projects and libraries. In these cases, MBX typically stands for words beginning with M, B, and X in the project title or description. Because MBX is not a standardized identifier, different projects with the same acronym are not related to one another beyond the shared initials.

Outside of software, MBX may appear in brand names, organizational codes, or product designations, further illustrating that the term serves as a flexible shorthand rather than a fixed concept. When encountering MBX, identifying the intended reference relies on contextual clues such as the field (computing, branding, or another domain), associated technologies, and accompanying terminology.

See also: mbox, mailbox, mailbox formats.