A user who sends an attachment receives back another file

We are using R5.08 client. When a user sends an attachment of any kind, the recipient receives another file (besides the original attachment) called stgxxxx (where x represents a number). The file, when viewed in a text editor, is unreadable. The Notes client seems to be generating these, because when the user uses iNotes to send attachments, it works properly (no extra attachments sent). One way to view these stgxxxx attachments is when the recipient uses a Web-based mail like Yahoo or Hotmail. I thought it could be related to a signature file but it wasn't. When an attachment is sent from one Notes client to another, the extra stgxxxx attachments do not show. Any ideas on where these extra attachments are coming from?
It sounds like the client is not set to send messages to the Internet in MIME format. Check the location document. It is most likely sending all messages in Notes Rich Text format.

This was first published in October 2003