mbox
What is a .mbox file?
application/mbox
An MBOX file is a mailbox that stores many email messages concatenated into one plain-text file, each message preceded by a 'From ' separator line. It is the classic Unix mailbox format used by many mail clients for export and archival.
How to use a .mbox file
Use an example MBOX to test mailbox splitting, message boundary detection, thread reconstruction, and import into a mail client or parser.