How to open winmail.dat on computer

Winmail.dat documents are often attached to extended text e-mails sent from Microsoft Outlook accounts that are configured incorrectly. In most cases, the format is not recognized by other mail programs other than Microsoft Outlook. To view the contents of documents with this attachment, you must use one of the methods of this article - change the text display settings in your email client profile. In addition, you can use third-party online text editing tools in such attachments.

How to open winmail.dat attachment

How to open winmail.dat? The easiest way to open it is to download third-party software. One of the best choices will be the Winmail.dat Reader. You can download the program from the official site.

Winmail.dat Reader window

Open, convert and save attachments to attachments sent by Microsoft Outlook and Exchange. Easy to use graphical user interface (without command line tool).

The Winmail.dat and ATT0001.dat documents are TNEF encoded information sent by Microsoft and Exchange. Users with other mail clients (for example, Mozilla or Lotus Notes) or platforms (for example, Android, Apple, iPad or iPhone) cannot open winmail.dat files.

To open the document, save the attached message on your hard disk, open the application for reading and click the "Open winmail.dat" button, and then specify the file previously saved in this format.

Another application is Winmail Opener. It has the traditional look and feel of Windows with a drop-down menu. The application also has all the capabilities of dragging and dropping Windows, so it's easy to move text and attachments from an email to a document or other place. The text is displayed in a central window with a scroll bar with attachments in the sidebar. This free application supports use in 13 languages ​​and is small, so it does not take up much space and does not require significant computer resources.

Winmail Opener window

Where do the winmail.dat files come from

Microsoft Outlook itself creates winmail.dat instead of an attachment when trying to send an email in RTF or HTML format. In this case, the program attach the file to the end of the e-mail.

Such a document contains information about formatting mail in an unreadable form for people. The email client uses this data to correctly format the email format.

Unfortunately, Outlook is the only email utility that uses the functions of a Winmail document. This means that anyone who does not use Outlook will also find this file when they receive and attempt to open an HTML or Rich Text email.

How to get rid of winmail.dat forever

Microsoft Outlook has many features, one of which is the ability to send emails using different text formats. This is the main reason for creating Winmail files, which may require additional programs to open. Such documents can cause problems for webmail users and email clients such as Eudora, Gmail, Yahoo, etc.

When Outlook sends formatted emails, it will in some cases activate TNEF text expansion. However, such a letter will open only Outlook. In other e-mail programs, all attachments fall into an unsupported winmail .dat file.

In the Thunderbird mail client, you can use the Lookout extension to decrypt messages with TNEF attachments. Download the add-on from the official Mozilla store and install it, then restart Thunderbird. From this point on, TNEF attachments will be decoded automatically, and the files contained in them will be displayed next to the winmail data file.

Mozilla Thunderbird Lookout Extension

You can also force Outlook to not send messages using the TNEF nested protocol. Click "Tools" - Options and go to the "Mail Format" tab. Set the "HTML" or "Plain Text" option in the "List of sent messages list" list.

Done! Now your emails will no longer contain such files, and recipients will be able to view them in full and without problems.