somethingmbox

Somethingmbox is an open, extensible format and accompanying software ecosystem for storing and organizing email messages. It extends the traditional mbox storage model by layering structured metadata, indexing, and optional encryption on top of a single-file or multi-file container. The design aims to improve portability, searchability, and long-term archiving of email collections while remaining compatible with existing mail clients through conversion tools.

Format and access: A somethingmbox archive consists of a sequence of messages, each preceded by a small index header containing metadata such as message-id, date, labels, and thread identifiers. The container may support compression, digital signatures, and integrity checks. Access libraries provide streaming reading, random access to messages by index, and incremental updates without rewriting the entire archive.

Features: Metadata support including tags, labels, and threading; cross-language libraries (Python, Go, Rust); tools to import/export from mbox, Maildir, and standard mail repositories; optional encryption at rest and in transit; integrity verification using checksums; and a pluggable indexing backend to support fast searches.

History and status: The concept behind somethingmbox emerged in the open-source community in the mid-2010s as an attempt to modernize email archiving. Several reference implementations and documentation have been published, with ongoing, community-driven development. It remains a niche format intended for archival, forensic, and research uses rather than general consumer email interchange.

See also: mbox, Maildir, Email archiving, Data formats, Digital forensics.