Knowledge Base

I'm not receiving the correct attachment to my email, I get a file called WINMAIL.DAT instead, what's wrong?

When an Outlook user composes and sends a message using either Rich Text Format or HTML Format, Outlook automatically generates a file, winmail.dat, and attaches it to the end of the message. winmail.dat contains formatting information, in a human-unreadable form, that Outlook will use on the receiving end to display this email message correctly. Unfortunately, Outlook is the ONLY email client program that can use this information! Other email client programs don't understand this information.

You can reply to the individual who sent you the offending email and ask that they re-send the message, with the attached files, as a plain text message, not in Rich Text Format or HTML.

If you are the person sending using Outlook and you want to know how to fix the problem, follow the directions below:

To Configure Outlook NOT to send Winmail.dat attachments, turn off Rich Text sending for messages in Microsoft Outlook.

1. Click on Tools
2. Click Options, and then click the Mail Format tab.
3. In the Send in this Message Format list, select Plain Text, and then click OK.

This will set your default sending method to Plain Text, which will lose your special formatting options with fonts, colors, etc. However everyone, no matter what email program they are using, will now be able to receive your email with no problems.