Outlook Express, formerly known as Microsoft Internet Mail and News, is a discontinued

email Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" meant ...

and

news client A newsreader is an application program that reads articles on Usenet distributed throughout newsgroups. Newsreaders act as clients which connect to a news server, via the Network News Transfer Protocol (NNTP), to download articles and post new ar ...

included with

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical user interface, graphical web browsers developed by Microsoft which was used in the Microsoft Wind ...

versions 3.0 through to 6.0. As such, it was bundled with several versions of

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

, from

Windows 98 Windows 98 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. The second operating system in the 9x line, it is the successor to Windows 95, and was released to ...

Windows Server 2003 Windows Server 2003 is the sixth version of Windows Server operating system produced by Microsoft. It is part of the Windows NT family of operating systems and was released to manufacturing on March 28, 2003 and generally available on April 24, 2 ...

, and was available for

Windows 3.x Windows 3.x means either of, or all of the following versions of Microsoft Windows: * Windows 3.0 * Windows 3.1x Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windo ...

, Windows NT 3.51,

Windows 95 Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1x, and was released to manufacturin ...

Mac System 7 System 7, codenamed "Big Bang", and also known as Mac OS 7, is a graphical user interface-based operating system for Macintosh computers and is part of the classic Mac OS series of operating systems. It was introduced on May 13, 1991, by Apple Co ...

Mac OS 8 Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis o ...

, and

Mac OS 9 Mac OS 9 is the ninth major release of Apple Inc., Apple's classic Mac OS operating system which was succeeded by macOS, Mac OS X (renamed to OS X in 2011 and macOS in 2016) in 2001. Introduced on October 23, 1999, it was promoted by Apple as "T ...

. In

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

, Outlook Express was superseded by

Windows Mail Mail (formerly Windows Mail) is an email client developed by Microsoft and included in Windows Vista and later versions of Windows. The main function of Mail is sending and receiving email. It is available as the successor to Outlook Express, wh ...

. Outlook Express is a different application from

Microsoft Outlook Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft Office and Microsoft 365 software suites. Though primarily an email client, Outlook also includes such functions as Calen ...

. The two programs do not share a common codebase, but they do share a common architectural philosophy. The similar names lead many people to conclude incorrectly that Outlook Express is a stripped-down version of Microsoft Outlook. Outlook Express uses the

Windows Address Book ''Windows Address Book'' was a component of Microsoft Windows that lets users keep a single list of contacts that can be shared by multiple programs. It is most commonly used by Outlook Express. It was introduced with Internet Explorer 3 in 1996 a ...

to store contact information and integrates tightly with it. On

Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct upgrade to its predecessors, Windows 2000 for high-end and ...

, it also integrates with

Windows Messenger Windows Messenger is a discontinued instant messaging client included in Windows XP. Designed for use by both corporate and home users, it was originally created, in 2001, as a streamlined and integrated version of MSN Messenger. It was upgrade ...

History

Version 1.0 was released as ''Microsoft Internet Mail and News'' in 1996 following the

Internet Explorer 3 Microsoft Internet Explorer 3 (IE3) is a graphical web browser which was announced in March 1996, and was released on August 13, 1996 by Microsoft for Microsoft Windows and on January 8, 1997 for Apple Mac OS (see IE for Mac). It began serious ...

release. This add-on precedes the ''Internet Mail'' profile for Microsoft Exchange 4.0 bundled in

. Version 2.0 was released at the end of 1996. Internet Mail and News handled only

plain text In computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects (floating-point numbers, images, etc.). It may also include a limit ...

and rich text ( RTF) email, lacking

HTML email HTML email is the use of a subset of HTML to provide formatting and semantic markup capabilities in email that are not available with plain text: Text can be linked without displaying a URL, or breaking long URLs into multiple pieces. Text is ...

. In 1997 the program was changed and renamed to ''Outlook Express'' and bundled with

Internet Explorer 4 Microsoft Internet Explorer 4 (IE4) is a graphical web browser that Microsoft unveiled in Spring of 1997, and released in September 1997, primarily for Microsoft Windows, but also with versions available for the classic Mac OS, Solaris, and H ...

. The Windows executable file for Outlook Express, ''msimn.exe'', is a holdover from the Internet Mail and News era. Like Internet Explorer, Outlook Express 4 can run on Mac System 7, OS 8, and OS 9. At one point, in a later beta version of Outlook Express 5, Outlook Express contained a sophisticated and adaptive

spam Spam may refer to: * Spam (food), a canned pork meat product * Spamming, unsolicited or undesired electronic messages ** Email spam, unsolicited, undesired, or illegal email messages ** Messaging spam, spam targeting users of instant messaging ( ...

filtering Filter, filtering or filters may refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Filter (software), a computer program to process a data stream * Filter (video), a software component tha ...

system; however this feature was removed shortly before launch. It was speculated on various websites and newsgroups at that time, that the feature was not stable enough for the mass market. Nearly two years later, a similar system, using a similar method of adaptive filtering, appeared as a feature of Microsoft Outlook.

Internet Explorer 5 Microsoft Internet Explorer 5 (IE5) is a graphical web browser, the fifth version of Internet Explorer, the successor to Internet Explorer 4 and one of the main participants of the first browser war. Its distribution methods and Windows integrat ...

required Outlook Express 5 to save Web Archive files (see

MHTML MHTML, an initialism of "MIME encapsulation of aggregate HTML documents", is a Web archive file format used to combine, in a single computer file, the HTML code and its companion resources (such as images) that are represented by external hyperl ...

). Outlook Express 6 is the last version of the software with Outlook branding. It has a similar layout to Outlook Express 5. It was included with Windows XP.

Supported file formats

* .DBX – Outlook Express Email Folder *.EMAIL - Outlook Express Email Message * .EML - E-Mail Message * .IDX - Outlook Express Mailbox Index File * .MBX - Outlook Express Mailbox * .MIM - Multi-Purpose Internet Mail Message File * .MIME - Multi-Purpose Internet Mail Extension * .MS-TNEF - MS Transport Neutral Encapsulation Format * .NCH - Outlook Express Folder File * .ODS - Outlook Express 5 Mailbox (not to be confused with

OpenDocument The Open Document Format for Office Applications (ODF), also known as OpenDocument, is an open file format for word processing documents, spreadsheets, presentations and graphics and using ZIP-compressed XML files. It was developed wi ...

spreadsheet file) * .OEB - Outlook Express Backup Wizard File * .PAB - Personal Address Book * .PST - Outlook Personal Information Store File * .SIG - Signature File * .VCF - vCard File * .WAB - Windows Address Book

Versions for Windows

* Microsoft Internet Mail and News 1.0 was released in 1996 with

. * Microsoft Internet Mail and News 2.0 was released later in 1996. * Outlook Express 4.0, which was included in

(June 1998) and integrated with

, stored messages in *.mbx files (similar to the

Mbox Mbox is a generic term for a family of related file formats used for holding collections of email messages. It was first implemented in Research Unix, Fifth Edition Unix. All messages in an mbox mailbox are concatenated and stored as plain text ...

format used in

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

-based systems). * Outlook Express 5.0, which was included in Windows 98 Second Edition (SE) (June 1999) and integrated with

, switched to *.dbx files, with a separate file for each mailbox folder. * Outlook Express 5.01 was included in

Windows 2000 Windows 2000 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It was the direct successor to Windows NT 4.0, and was Software release life cycle#Release to manufacturing (RTM), releas ...

(February 2000) and integrated with Internet Explorer 5.01. * Outlook Express 5.5 was included in

Windows Me Windows Millennium Edition, or Windows Me (marketed with the pronunciation of the pronoun "me"), is an operating system developed by Microsoft as part of its Windows 9x family of Microsoft Windows operating systems. It is the successor to Windo ...

(June 2000) and integrated with Internet Explorer 5.5. * Outlook Express 6.0 was included in

(October 2001) and integrated with

Internet Explorer 6 Microsoft Internet Explorer 6 (IE6) is a graphical web browser developed by Microsoft for Windows operating systems. Released on August 24, 2001, it is the sixth, and by now discontinued, version of Internet Explorer and the successor to Internet ...

Versions for Mac

* Outlook Express 4.0 was included in

Microsoft Office 98 Macintosh Edition Microsoft Office 98 Macintosh Edition is a version of Microsoft Office for the classic Mac OS, unveiled at Macworld Expo/San Francisco on January 6, 1998. It introduced the Internet Explorer 4.0 browser and Outlook Express, an Internet e-mail clie ...

. * Outlook Express 5.01 was integrated with Internet

Explorer 5 Explorer 5 was a United States satellite with a mass of . It was the last of the original series of Explorer satellites built, designed, and operated by the Jet Propulsion Laboratory. Background Explorer 5 was similar in all respects to Ex ...

. * Outlook Express 5.01 was bundled with Internet Explorer 5.01. * Outlook Express 5.5 was bundled with Internet Explorer 5.5.

Replacements

Builds of "Outlook Express 7" appeared in early builds of

when in development as "Longhorn". It relied on

WinFS WinFS (short for Windows Future Storage) was the code name for a canceled data storage and management system project based on relational databases, developed by Microsoft and first demonstrated in 2003 as an advanced storage subsystem for the Micro ...

for the management and storage of contacts and other data. The final version of Vista included a successor to Outlook Express known as

Windows Mail (Vista) Mail (formerly Windows Mail) is an email client developed by Microsoft and included in Windows Vista and later versions of Windows. It is available as the successor to Outlook Express, which was either included with, or released for Internet Ex ...

Criticism

Email standards

Beginning with the text-based Unix Mail command, email traditionally used the inline or bottom posting styles when replying to messages. Outlook Express, as well as

Lotus Notes HCL Notes (formerly IBM Notes and Lotus Notes; see Branding below) and HCL Domino (formerly IBM Domino and Lotus Domino) are the client and server Server may refer to: Computing *Server (computing), a computer program or a device that provide ...

and Microsoft Outlook, top-post (show replies newest to oldest) by default. Microsoft Outlook and Microsoft Exchange use a

proprietary {{Short pages monitor