Windat attachments, Recipient problems with attachments in Outlook

Occasionally we receive email message questions surrounding a  strange file being attached to emails.  Variations include Windat, winmail.dat and webmail.dat. Recipients cannot open the file and discern any contents. 

Different email client programs that receive, read, and send email are the culprits The most commonly used email client programs are Microsoft Outlook, Outlook Express and Netscape, with some people using Eudora. Outlook can cause troubles not for the sender of the email, but the recipient, particularly when actual files are attached to messages like PDF files. 

Problem: 
The file winmail.dat (or webmail.dat or windat) retains the format (e.g. fonts) of sending a message in Rich Text Format (RTF) to another Outlook recipient. However, it cannot be recognized by other email clients including Outlook Express, Eudora etc.

Solution details if you want to change your default sending mode

1. On the Tools menu, click options.

2. Choose the Mail Format.
3. In the Compose in this message format area, select Plain Text from the drop-down box.
4. and then click OK

Solution details if you do not want to send in plain text to all people.

If the recipient is in your address book

1. Open up your Outlook Address Book, either by clicking on the Address Book icon or by choosing Tools->Address Book Select the recipient's entry in your address book and open up their Properties, either by clicking on the Properties button or double- clicking on the recipient's entry.
2. Select the "Name" tab in the Properties dialog window.
3. Check the box at the bottom of the window that says "Send email using plain text only".
4. Click the "OK" button.

If you enter the recipient's address manually in the To: line of your email message

1. Create a new email message as you normally would, but before sending it,
2. Choose Format->Plain Text from the menu bar.
3. Now send your message.