Transport Neutral Encapsulation Format

Last updated

Transport Neutral Encapsulation Format or TNEF is a proprietary email attachment format used by Microsoft Outlook and Microsoft Exchange Server. An attached file with TNEF encoding is most often named winmail.dat or win.dat, and has a MIME type of Application/MS-TNEF. The official (IANA) media type, however, is application/vnd.ms-tnef. [1]

Contents

Overview

Some TNEF files contain information used only by Outlook to generate a richly formatted view of the message, such as embedded (OLE) documents or Outlook-specific features such as forms, voting buttons, and meeting requests. Other TNEF files may contain files which have been attached to an e-mail message.

Within the Outlook e-mail client, TNEF encoding cannot be explicitly enabled or disabled (except via a registry setting [2] ). Selecting RTF as the format for sending an e-mail implicitly enables TNEF encoding, using it instead of the more common and widely compatible MIME standard. When sending plain text or HTML format messages, some versions of Outlook (apparently including Outlook 2000 [3] ) prefer MIME, but may still use TNEF under some circumstances (for example, if an Outlook feature requires it). [3] [4]

TNEF attachments can contain security-sensitive information such as user login name and file paths, [3] [4] from which access controls could possibly be inferred.

Exchange Server

Native-mode Microsoft Exchange 2000 organizations will, in some circumstances, send entire messages as TNEF-encoded raw binary independent of what is advertised by the receiving SMTP server. As documented in Microsoft KBA #323483, [5] this technique is not RFC-compliant because these messages have the following characteristics:

Internal communications between Exchange Servers (2000 and later) over SMTP encode the message in S/TNEF (Summary TNEF) format. The conversion between the format needed by the end client on the Internet is performed on the last Hub Transport server before final delivery, and when the Hub Transport role of an Exchange Server is about to deliver the message to a mailbox role server, the message is converted to MAPI format for storage.

S/TNEF differs from TNEF in that it is 8-bit (not 7-bit for TNEF) and does not contain a plain-text portion.

Decoding

Programs to decode and extract files from TNEF-encoded attachments are available on many platforms.

Multiplatform

Unix-like or POSIX command-line

Mac

iPhone and iPad

Microsoft Windows

Android

Online

Software libraries

Related Research Articles

<span class="mw-page-title-main">Email</span> Mail sent using electronic means

Electronic mail is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.

Multipurpose Internet Mail Extensions (MIME) is a standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message bodies may consist of multiple parts, and header information may be specified in non-ASCII character sets. Email messages with MIME formatting are typically transmitted with standard protocols, such as the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP), and the Internet Message Access Protocol (IMAP).

<span class="mw-page-title-main">Microsoft Office</span> Suite of office software

Microsoft Office, or simply Office, is a family of client software, server software, and services developed by Microsoft. It was first announced by Bill Gates on August 1, 1988, at COMDEX in Las Vegas. Initially a marketing term for an office suite, the first version of Office contained Microsoft Word, Microsoft Excel, and Microsoft PowerPoint. Over the years, Office applications have grown substantially closer with shared features such as a common spell checker, Object Linking and Embedding data integration and Visual Basic for Applications scripting language. Microsoft also positions Office as a development platform for line-of-business software under the Office Business Applications brand.

<span class="mw-page-title-main">Microsoft Outlook</span> Email and calendaring software

Microsoft Outlook is a personal information manager software system from Microsoft, available as a part of the Microsoft 365 software suites. Though primarily being popular as an email client for businesses, Outlook also includes functions such as calendaring, task managing, contact managing, note-taking, journal logging, web browsing, and RSS news aggregation.

<span class="mw-page-title-main">Outlook Express</span> Microsoft e-mail client software

Outlook Express, formerly known as Microsoft Internet Mail and News, is a discontinued email and news client included with Internet Explorer versions 3.0 through 6.0. As such, it was bundled with several versions of Microsoft Windows, from Windows 98 to Windows Server 2003, and was available for Windows 3.x, Windows NT 3.51, Windows 95, Mac System 7, Mac OS 8, and Mac OS 9. In Windows Vista, Outlook Express was superseded by Windows Mail.

<span class="mw-page-title-main">Apple Mail</span> Email client by Apple Inc.

Mail is an email client included by Apple Inc. with its operating systems macOS, iOS, iPadOS, watchOS, and visionOS. Mail grew out of NeXTMail, which was originally developed by NeXT as part of its NeXTSTEP operating system, after Apple's acquisition of NeXT in 1997.

<span class="mw-page-title-main">The Bat!</span> Email client for Windows

The Bat! is an email client for the Microsoft Windows operating system, developed by Moldovan software company Ritlabs. It is sold as shareware and offered in three editions: Home Edition, Professional Edition, and Voyager which is a portable version and is included with Professional Edition.

<span class="mw-page-title-main">Pegasus Mail</span> Proprietary email client

Pegasus Mail is a proprietary email client for Microsoft Windows. It was originally released in 1990 on NetWare networks with MS-DOS and later Apple Macintosh clients, before being ported to Windows which is now the only platform actively supported. Since its inception it has been developed by David Harris and is donationware after having previously been freeware.

<span class="mw-page-title-main">Microsoft Entourage</span> Email client and personal information manager

Microsoft Entourage is a discontinued e-mail client and personal information manager that was developed by Microsoft for Mac OS 8.5 and later. Microsoft first released Entourage in October 2000 as part of the Microsoft Office 2001 office suite; Office 98, the previous version of Microsoft Office for the classic Mac OS included Outlook Express 5. The last version was Entourage: Mac 2008, part of Microsoft Office 2008 for Mac, released on January 15, 2008. Entourage was replaced by Outlook for Macintosh in Microsoft Office for Mac 2011, released on October 26, 2010.

An email attachment is a computer file sent along with an email message. One or more files can be attached to any email message, and be sent along with it to the recipient. This is typically used as a simple method to share documents and images.

An IFilter is a plugin that allows Microsoft's search engines to index various file formats so that they become searchable. Without an appropriate IFilter, contents of a file cannot be parsed and indexed by the search engine.

<span class="mw-page-title-main">Claws Mail</span> E-mail client software

Claws Mail is a free and open-source, C/GTK-based e-mail client, which is both lightweight and highly configurable. Claws Mail runs on both Windows and Unix-like systems such as Linux, BSD, and Solaris. It stores mail in the MH mailbox format. Plugins allow to read HTML mail, but there is none to compose HTML messages.

<span class="mw-page-title-main">Windows Live Mail</span> Email client, electronic calendar and newsreader, developed by Microsoft

Windows Live Mail is a discontinued freeware email client from Microsoft. It was the successor to Windows Mail in Windows Vista, which was the successor to Outlook Express in Windows XP and Windows 98. Windows Live Mail is designed to run on Windows 7 and Windows Server 2008 R2, but is also compatible with Windows 8 and Windows 10, even though Microsoft bundles a new email client, named Windows Mail, with the latter. In addition to email, Windows Live Mail also features a calendar, an RSS feed reader, and a Usenet newsreader.

<span class="mw-page-title-main">Outlook.com</span> Microsoft webmail service

Outlook.com, formerly Hotmail, is a free personal email service offered by Microsoft. This includes a webmail interface featuring mail, calendaring, contacts, and tasks services. Outlook can also be accessed via email clients using the IMAP or POP protocols.

An rpmsg file is a file format containing a restricted-permission message. It is used to implement IRM for Outlook messages with the aim of controlling access to content via encryption and access controls, and restricting certain actions such as the ability to forward or copy.

<span class="mw-page-title-main">Microsoft Office for Mac 2011</span> Version of Microsoft Office for Mac released in 2011

Microsoft Office for Mac 2011 is a version of the Microsoft Office productivity suite for macOS. It is the successor to Microsoft Office 2008 for Mac and is comparable to Office 2010 for Windows. Office 2011 was followed by Microsoft Office 2016 for Mac released on July 9, 2015, requiring a Mac with an x64 Intel processor and OS X Yosemite or later. Office for Mac 2011 is no longer supported as of October 10, 2017. Support for Lync for Mac 2011 ended on October 9, 2018.

<span class="mw-page-title-main">Microsoft Outlook (mobile app)</span> Mobile email and calendaring application

The Microsoft Outlook mobile app is a mobile personal information manager (PIM) for Android and iOS devices.

Acompli is a discontinued mobile app that allowed for user interaction with email messages as well as management of multiple email accounts in one programme. In addition, the tool also organized one's calendar and shared files. This application provided for integration with cloud storage platforms such as Dropbox, OneDrive, and iCloud; it also carried support for Microsoft Exchange and Gmail. Acompli launched on 24 April 2014. The startup company, which had $7.3 million in funding, was led by CEO Javier Soltero, J.J. Zhuang (CTO) and Kevin Henrikson.

<span class="mw-page-title-main">Mail (Windows)</span> Conflation of two applications developed by Microsoft

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 Explorer 3.0 and later versions of Internet Explorer. It is set to be replaced by Outlook for Windows.

<span class="mw-page-title-main">Geary (e-mail client)</span> Open-source email client

Geary is a free and open-source email client written in Vala and based on WebKitGTK. Although since adopted by the GNOME project, it originally was developed by the Yorba Foundation. The purpose of this e-mail client, according to Adam Dingle, Yorba founder, was to bring back users from online webmails to a faster and easier to use desktop application.

References

  1. "Some Microsoft Media Types for registration". IANA. Retrieved October 25, 2010.
  2. "When you use Outlook 2007 to send an e-mail message, the recipient of the message sees an attachment that is called Winmail.dat". Microsoft. July 29, 2009. Retrieved March 3, 2011.
  3. 1 2 3 "Description of Transport Neutral Encapsulation Format (TNEF) in Outlook 2000". Microsoft. Archived from the original on September 4, 2009. Retrieved September 11, 2009.
  4. 1 2 "How e-mail message formats affect Internet e-mails in Outlook". Microsoft. March 30, 2005. Retrieved October 13, 2006.
  5. Microsoft KBA #323483
  6. "Claws Mail - Plugins". www.Claws-Mail.org. Retrieved December 23, 2017.
  7. "LookOut". addons.Mozilla.org. September 30, 2011. Retrieved December 23, 2017.
  8. "LookOut (fix version)". addons.Mozilla.org. Retrieved December 23, 2017.
  9. "mozdev.org - lookout: index". lookout.MozDev.org. Retrieved December 23, 2017.
  10. "77811 - Inline viewer for Microsoft proprietary mail formats (ms-tnef, etc.) ["winmail.dat"]". bugzilla.Mozilla.org. Retrieved December 23, 2017.
  11. "KTnef". KDE Gitlab.
  12. 1 2 Yeraze (November 21, 2017). "ytnef: Yeraze's TNEF Stream Reader - for winmail.dat files" . Retrieved December 23, 2017 via GitHub.
  13. Simpson, Mark (December 8, 2017). "tnef" . Retrieved December 23, 2017 via GitHub.
  14. "Klammer on the Mac App Store". Mac App Store. Retrieved December 23, 2017.
  15. "MailRaider Pro on the Mac App Store". Mac App Store. Retrieved December 23, 2017.
  16. "Winmail Viewer - Open and Read Winmail.dat Files on the Mac App Store". Mac App Store. Retrieved December 23, 2017.
  17. "Josh Jacob - TNEF's Enough". www.JoshJacob.com. Retrieved December 23, 2017.
  18. "tnefDD". SourceForge.net. Retrieved December 23, 2017.
  19. (mij@macports.org), Jim Mock. "The MacPorts Project -- Available Ports". www.MacPorts.org. Retrieved December 23, 2017.
  20. "Letter Opener". Restoroot.org. Archived from the original on November 2, 2006. Retrieved December 23, 2017.
  21. "Winmail File Viewer on the App Store". App Store. Retrieved January 8, 2018.
  22. "WinMail.dat Viewer for OS 10 on the App Store". App Store. July 11, 2017. Retrieved January 8, 2018.
  23. "Winmail Viewer for iPhone and iPad on the App Store". App Store. July 12, 2017. Retrieved January 8, 2018.
  24. "Klammer on the App Store". App Store. Retrieved January 8, 2018.
  25. "WinDat Opener on the App Store". App Store. Retrieved January 8, 2018.
  26. "Connecting to the iTunes Store". iTunes.apple.com. Retrieved January 8, 2018.
  27. "TNEF's Enough". App Store. February 2, 2020. Retrieved March 17, 2020.
  28. 1 2 "Winmail.dat Reader - Open winmail.dat files (Freeware)". www.Winmail-dat.com. Retrieved December 23, 2017.
  29. "Winmail Opener - freeware utility for opening winmail.dat and other TNEF-encoded files". www.Eolsoft.com. Retrieved December 23, 2017.
  30. Petersen, Frank. "tnef(TO)win, convert mstnef-attachments". www.Petersen.de. Retrieved December 23, 2017.
  31. "PDF, DOC, DOCX, DAT, BIN, PHP Viewer - FreeFileViewer". www.FreeFileViewer.com. Retrieved December 23, 2017.
  32. "Welcome to Fentun's Home Page". www.Fentun.com. Archived from the original on November 26, 2004. Retrieved December 23, 2017.
  33. "Get Winmail.dat Viewer - Letter Opener - Microsoft Store". Microsoft Store. Retrieved December 23, 2017.
  34. "Tools / TNEF Extractor · GitLab" . Retrieved June 22, 2020.
  35. "Winmail.dat Opener". Google.com. Retrieved December 23, 2017.
  36. grapph.com, Milos Wikarski. "Free Online Document Converter". doc2any.Grapph.com. Retrieved December 23, 2017.
  37. "Online version - Winmail.dat Reader". www.Winmail-dat.com. Retrieved December 23, 2017.
  38. "MS-TNEF degenerator". tud.at. Retrieved December 23, 2017.
  39. "www.winmaildat.com". Winmaildat.com. Retrieved December 23, 2017.
  40. "the-computer-site.com - The Computer Site - Extract Attachments from WINMAIL.DAT files". The-Computer-Site.com. Retrieved December 23, 2017.
  41. "JTNEF - Java TNEF package". www.FreeUtils.net. Retrieved January 8, 2018.
  42. "POI-HMEF - Java API To Access Microsoft Transport Neutral Encoding Files (TNEF)". poi.Apache.org. Retrieved January 8, 2018.
  43. "MVCOM - MAPI-Free COM component for Outlook .pst, .msg, .ost". www.Encryptomatic.com. Retrieved January 8, 2018.
  44. "Convert::TNEF - Perl module to read TNEF files - metacpan.org". Metacpan.org. Retrieved January 8, 2018.
  45. "tnefparse: a TNEF decoding library written in python, without external dependencies". October 18, 2017. Retrieved January 8, 2018 via GitHub.
  46. Sheikh, Farrukh. "Outlook Alternative - Email APIs for .NET Java Android SharePoint Cloud". www.Aspose.com. Retrieved January 8, 2018.
  47. "IMAP4 Component, POP3 Component, Email Parser for C#, VB, C++, Delphi - Retrieve Email, Parse Email, Decrypt Email, S/MIME, Parse winmail.dat, TNEF, Parse Outlook Msg, SSL, TLS". www.EmailArchitect.net. Retrieved January 8, 2018.
  48. Murphy, John. "node-tnef" . Retrieved August 31, 2018.
  49. "MimeKit.Tnef Namespace". www.mimekit.net. Retrieved December 22, 2022.
  50. "github.com/QualityUnit/TNEFDecoder". GitHub .