Mbox

Mbox is a generic term for a family of related <a href="/facts/File_format/qrXbwJaH">file formats</a> used for holding collections of <a href="/facts/Email/6pD9GLtI">email</a> messages. It was first implemented in <a href="/facts/Research_Unix/5oWmUdwo">Fifth Edition Unix</a>.
All messages in an mbox mailbox are <a href="/facts/Concatenation/1npYg6rc">concatenated</a> and stored as <a href="/facts/Plain_text/TSlSSAg2">plain text</a> in a single file. Each message starts with the four characters "From" followed by a space (the so-called "From_ line") and the sender's email address. RFC 4155 defines that a <a href="/facts/UTC/2EnjfSyu">UTC</a> timestamp follows after another separating space character.
A format similar to mbox is the <a href="/facts/MH_Message_Handling_System/f4CBduT8">MH Message Handling System</a>. Other systems, such as <a href="/facts/Microsoft_Exchange_Server/9pu8G4It">Microsoft Exchange Server</a> and the <a href="/facts/Cyrus_(imapd)/F6A5wpej">Cyrus IMAP</a> server, store mailboxes in centralized databases managed by the mail system and not directly accessible by individual users. The <a href="/facts/Maildir/styR8olS">maildir</a> mailbox format is often cited as an alternative to the mbox format for networked email storage systems.

Mbox open-in-new

Mbox