The Problem
When you use Microsoft Outlook to send email with attachments and you use "Microsoft Outlook Rich Text Format" Recipients who do not use Outlook may report that the message includes a file attachment called winmail.datThe Cause
This problem occurs because the Winmail.dat includes Rich Text Formatting (RTF) instructions and the attachment files. This type of formatting is used with Microsoft Outlooks Rich Text format and when you use Microsoft Word as your e-mail editor.The Solution
To resolve this problem, use the plain text format
- On the Tools menu, click Options, and then click Mail Format
- In Compose in this message format, click to select Plain Text, and then click OK
NOTE: To send to certain recipients that use RTF format and others recipients that use plain text format, you must set the option for the recipient in either the Personal Address Book or the recipient's contact record
How to remove the RTF format from the recipient in your Personal Address Book
- On the Tools menu, click "Address Book"
- In Show Names From, click "Personal Address Book"
- Select the address(es) that you want to set as plain text, then click "Properties" on the File menu
- In the SMTP "General" tab, clear the "Always send to this recipient in Microsoft Exchange rich text format" check box, then click "OK"
How to set Plain Text in the recipient's contact record
- Open the recipient's contact record in the Contacts folder
- Double-click the recipient's e-mail address
- In the E-Mail Properties dialog box, click "Send Plain Text Only" under Internet Format