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If you receive winmail.dat attachments in Mailspring and would like to open them, you can find utilities for Mac, Linux and Windows that allow you to decode the proprietary TNEF format. Many IT departments also configure Microsoft Exchange not to send winmail.dat files outside their corporate firewall, which is considered a best practice by many Exchange administrators. Right-click on the file and hover on Open with, then click Choose another app: Click on More apps: Check the list for your media player and choose it, then select OK: The file will be opened by the media player you chose: Repeat the process if you are sure of the information the DAT file contains. The easiest way to handle them is to get your correspondent to not send you 'rich text' format emails from Microsoft Outlook: These attachments contain formatting information in Microsoft's proprietary TNEF format, but they cannot be read by many other email clients including Mailspring. The second is an MSF file, which is also known as a Mail Summary file with. The first one is an MBOX file (without extension), which is a standard format of Mozilla Thunderbird client to store Email content. Go to your DAT file's location, then click once the DAT file to select it.
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This will allow the File Explorer to display all files, including your DAT file. discovered that also has all the features I wanted in a blog reader. The Thunderbird stores user data (Email) in two parts. Click the file type box to the right of the 'Name' text field, then click All Files in the resulting drop-down menu.
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If you receive email from people using older versions of Microsoft Outlook, you may see winmail.dat attachments on messages. Every time I backup my data files, I also backup all my Thunderbird email messages.
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