Outlook 2000, attachments disappear

[ATC]

When sending email with attachments, the attachments disappear for no apparent reason.

[ATC]

This is a fantastic new "feature" "innovated" by Microsoft. Instead of sticking to the de facto standard MIME format, they have invented their own standard called TNEF.

According to MSKB, changing your default mail format to Plain Text or HTML will help ensure that TNEF is not sent unless an Outlook feature needs it. Exactly what features "need" TNEF is not mentioned.

Source:
http://support.microsoft.com/support/kb/articles/Q241/5/38.ASP