Opening MBX Files

The MBX file type is primarily associated with Outlook Express.

MBX	File extension: MBX
	File type:	mailbox file

What is an MBX file?

MBX files mostly belong to Outlook Express by Microsoft. MBX stands for MailBox file and is used as a data file by the mail application Outlook Express developed by Microsoft.

Main Use: MBX files are used to store Outlook Express e-mails data. These MBX files consist of actual email data saved in a plain text format. These files consist of all the emails sent or received by the Outlook Express user and can be used to backup email messages by saving a copy of the existing MBX files to a different folder. MBX files were initially used in collectively storing email messages on UNIX-based operating systems. Each message usually starts with the From_ line and finishes with a blank line. The email message is stored between the two lines in an RFC 2822 format. Since then, MBX files have been used by multiple mail clients apart from Outlook Express such as Eudora, Pipe, Netscape, and PocoMail.
Other Uses: MBX file extension is also used by the relational database management software dBase, to store index related information. MapBasic also uses the MBX file format. MapBasic is a programming language used in the creation of additional Windows compatible tools related to MapInfo software. These MBX files consist of compiled MapBasic program data.

How to open MBX files

You need a suitable software like Outlook Express to open an MBX file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your MBX file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a MBX file directly in the browser:. Just drag the file onto this browser window and drop it.

Online MBX Text Viewer

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Programs that open and convert MBX files:

Outlook Express by Microsoft
See the previous paragraphs to learn more about the main application. MBX files are often referred to as Outlook Express data files because this type of file is primarily created or used by this software.
Eudora (mailbox file) by Computer History Museum
Eudora, an open-source e-mail client program, supports both POP and IMAP protocols and is developed for Apple macOS and Microsoft Windows operating systems. It also supports palmtop platforms like Palm OS and Newton. On May 22, 2018, the Computer History Museum acquired full ownership of Eudora. This file format is classified as Data. Related links: Eudora on Wikipedia, Manual
MapBasic (executable application file) by Pitney Bowes
MapBasic is a BASIC-like programming language used to create custom additional tools and functionality for the MapInfo Professional geographical information system. MapBasic also allows software development in other programming languages like C, C++, and Visual Basic - and creates an electronic mapping along with the MapInfo Professional GIS. This software is using the MBX file as application executable. This file format is classified as Developer. Related links: User Guide, Support, MapBasic on Wikipedia
Thunderbird (mailbox file) by Mozilla
Mozilla Thunderbird is a free and open-source cross-platform email application, personal information manager, news client, RSS web feed client, and chat client. Mozilla announced on January 28, 2020, that they will transfer the Thunderbird operations to a new wholly-owned subsidiary - MZLA. This file format is classified as Data. Related links: Manual, Support

MBX file format details:

Every file has a defined file format, i.e. how the data is arranged in the file. The first characters in a file identify the file format, for example, HTML files start with the bytes <html>. However, different programs can use the same file extension, and file extensions can be assigned incorrectly. So a detailed analysis of a file is vital in order to determine the format and the associated program. Below is our analysis of the MBX files:

The MBX file extension covers different formats for different programs. The following file formats are most commonly found in MBX files:

30% of all MBX files start with the bytes From, which are crucial for this file format. The contents of these files can even be read by a human. Most of these files are 2 KB to 15 MB in size. This file type was primarily in use more than 20 years ago. The following keywords are characteristic: From ???@???, Received: from and Return-Path. Some examples of file names are In.mbx or Out.mbx. Such files are related to mailbox, gledhill and rame.
25% of all MBX files use the same file format, which can be identified by the letters "JMF6" at the beginning. These files are not pure binary files and are therefore readable and interpretable with a text editor. The average file size is 10 MB with most files being between 10 KB and 850 MB in size. Several words can almost always be found in the files, e.g. JMF6 and From. The following filename is common: file20180601.mbx or Inbox.mbx. Such files sometimes refer to folder, items, ordner and sent.

All other MBX files (45%) have no consistent format, the following 5 formats exist: MapInfo MapBasic application eXtension, mbx and Multimedia. Sometimes used for friends. If you want to find out which format your MBX file belongs to, just click on the button "Choose your .mbx file to analyze".

Technical Data for MBX File Extension

File classification:

Data

Related files:

mbox, idx, toc, msf, dbx, zip, mdx, msg, txt, sdf, nws, boe, lko

Mime type:

application/mbox

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: Eudora.Mailbox
EXEFile: %ProgramFiles%\Eudora52\Eudora.exe %1

ProgramID: Eudora.Mailbox
EXEFile: %ProgramFiles%\Eudora\Eudora.exe %1

ProgramID: Eudora.Mailbox
EXEFile: %ProgramFiles%\Qualcomm\Eudora\Eudora.exe %1

ProgramID: Eudora.Mailbox
EXEFile: C:\Eudora\Eudora.exe %1

ProgramID: Eudora.Mailbox
EXEFile: C:\INTERNET\eudora\WORKER~1\Eudora.exe %1

ProgramID: Eudora.Mailbox
EXEFile: E:\@B\eudora\dair04\Eudora.exe %1

ProgramID: mbxfile
EXEFile: %ProgramFiles%\MapInfo\Professional\Mapinfow.exe -noexec %1

ProgramID: MailNavigator Mail Box
EXEFile: %ProgramFiles%\MailNavigator\MailNavigator.exe open %1

ProgramID: Eudora.Mailbox
EXEFile: C:\Qualcomm\Eudora\Eudora.exe %1

ProgramID: mbxfile
EXEFile: H:\Nkacoale\MapInfo\Mapinfow.exe -noexec %1

ProgramID: mbxfile
EXEFile: %ProgramFiles%\MapInfo\Professional\Mapinfow.exe

ProgramID: Eudora.Mailbox
EXEFile: %ProgramFiles%\Qualcomm\EUDORA~1\Eudora.exe

Show all 12 listings To Top

an mbx mailbox file is a special file format by Microsoft and should only be edited and saved with the appropriate software.

How to solve problems with MBX files

Associate the MBX file extension with the correct application.
Update your software that should actually open mailbox files. Because only the current version supports the latest MBX file format. Search, therefore, e.g. on the Microsoft manufacturer website after an available Outlook Express update.
To make sure that your MBX file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .MBX file online - secure, fast, and no downloads needed.