I have two different people asking me why outlook express is sending two emails when they only send a single email. One of these is getting read receipts (two of them from different people they sent different emails to) and the other person gets phone calls. I have unchecked the "send messages immediately" and "reply to messages using the format in which they were sent" also switched the mail sending format from HTML to plain text. To my knowledge only emails with attachments, so I'm thinking it may have something to do with our server or the virus protection on the recipient end. Anyone have any ideas?