How Do You Open Winmail.dat Attachments?

How Do You Open Winmail.dat Attachments?

Recipients of winmail.dat attachments can open these files by using a free Web-based utility that provides data extraction service. The online viewer at enables users to directly avail of this resource without the need to download and install the tool.

Email senders using Microsoft's Office Outlook or MS Exchange Server, may unknowingly include a winmail.dat file attachment to their message. This file type uses a compression format that is not supported by other major email clients. Those who receive a winmail.dat attachment usually require a special software to gain access to the file's content.

The steps below provide a quick and easy guide on how to use the free online data extractor at It should be noted that the maximum file size that can be uploaded in only five megabytes.

  1. Save a copy of the winmail.dat attachment
  2. Open a web browser. Log on to the email account and download the relevant file. Save it on a computer.

  3. Navigate to
  4. Find the link to using a search engine or type "" on the browser's address bar.

  5. Upload the file
  6. Click on "Choose File" under the "Extract" tab. Browse the system and locate the attachment from the computer's directory. Click on the appropriate file and then select "Open" to proceed. Click the "Send file" button to start the upload process.

  7. Download the extracted contents
  8. Access the decompressed components under the "Results" tab. Click on the extracted files to download.