Web hosting: Why am I seeing windat files in my webmail?

Our web hosting helpdesk team explains how to deal with the windat files in your mail.

winmail.dat files are created by Outlook and are designed to be read, unfortunately, only by other Outlook users. It is a closed Microsoft proprietary format and contains the content of the email plus any attachments, all bundled together.

You can either ask the sender to resend the email again, but this time as plain text or html (see below on advice on what the sender needs to do). Or there is free software available to download designed to solve this annoying problem by allowing you to open winmail.dat files.

You can search the internet for links, or you can try Winmail Opener www.eolsoft.com/freeware/winmail_opener/ It is a simple install and then you just use it to open the winmail.dat attachment.

Avoid creating windat files


  1. How to specify e-mail format in Microsoft Office Outlook 2007
  2. On the Tools menu, click Options.
  3. Click the Mail Format tab.
  4. In the Compose in this message format box, click Plain Text or HTML, and then click OK.





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