Have you ever sent an email with a PDF attachment, only to have the recipient tell you they received a winmail.dat file instead? If so, you’re not alone. This is a common issue that many people encounter, especially when using Microsoft Outlook. But don’t worry, there’s a simple solution to this problem, and we’re going to walk you through it step by step.

What is the Winmail.dat Issue?

Before we dive into the solution, let’s first understand the problem. The winmail.dat file is a data file that Microsoft Outlook uses to preserve certain formatting elements when an email is sent. This includes things like fonts, colors, and other layout elements. However, not all email clients can interpret these files, which is why some recipients might receive a winmail.dat file instead of the intended PDF attachment.

How to Fix the Winmail.dat Email Issue

Now, let’s get to the solution. The key to fixing this issue lies in changing the way your emails are formatted. Here’s a step-by-step guide on how to do this:

  1. Open Microsoft Outlook: The first step is to open your Microsoft Outlook application. This is where you’ll be making the necessary changes.
  2. Go to File Options: Once you have Outlook open, navigate to the ‘File’ tab at the top of the screen, and select ‘Options’ from the dropdown menu.
  3. Change Email Format: In the Options window, go to the ‘Mail’ category. Here, you’ll see an option to change the format of your emails. You’ll want to change this from ‘Rich Text’ to either ‘Plain Text’ or ‘HTML’. This will prevent Outlook from creating winmail.dat files in the future.
  4. Save Changes: After making these changes, click ‘OK’ to save them. You can then close the Outlook application.

And that’s it! With these simple steps, you should be able to fix the winmail.dat email issue. The next time you send an email with a PDF attachment, your recipient should receive the correct file.


While the winmail.dat issue can be frustrating, it’s relatively easy to fix, even for non-techies. By changing your email format in Microsoft Outlook, you can ensure your attachments are received correctly. So, don’t let this minor issue stand in the way of your communication. Follow these steps and keep your emails flowing smoothly.