File Type Email Mailbox File IconEmail Mailbox File
File Format Standard
Usage Referenced by an application; not meant to be opened manually; may run a program or script when opened
Rank ★ ★ ☆  Average

Mail format created for organizing and storing e-mail messages in a single text file; originally used by Unix hosts to store e-mail messages locally; messages saved in an MBOX file are concatenated one after another, starting with the "From" header.

Apple Mail 1.x (included with Mac OS X) saved messages in MBOX files and stored them in the /User/Library/Mail/Mailboxes/ folder. Apple 2.0 and later uses .EMLX format, which separates the messages into individual files so they can be searched by the Spotlight program.

The MBOX mail format is still used by several other e-mail programs, including those listed below.

Open With

IconMozilla Thunderbird

IconCoolUtils Total Thunderbird Converter

IconKernel MBOX Viewer


IconApple Mail

IconMicrosoft Outlook for Mac

IconMozilla Thunderbird


IconMozilla Thunderbird

IconGNOME Evolution

Updated 2007
Information from the PC File Extensions Reference