See http://support.microsoft.com/?kbid=241538
<EXCERPT> Controlling TNEF in Mail Messages: TNEF can be controlled in three places, and is different depending on your installation of Outlook (Internet Mail Only, or Corporate or Workgroup). Global: Changing your default mail format to Plain Text or HTML will help ensure that TNEF is not sent unless an Outlook feature needs it. Per Message: If the message is a Rich Text Format (RTF) message, and you are using the Internet Mail Only (IMO) installation of Outlook, you can turn on or turn off TNEF for one message at a time. Per Recipient: You can specify in the recipient's e-mail address to not send TNEF, so that a recipient always receives plain text versions of the message. [... snip ...] Problem: Recipient receives ATT00001.DAT attachment. Solution: Turn TNEF off (either for the recipient, or globally). </EXCERPT> Or just change it to plain text before posting, or make a custom toolbar button for each -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]