If you're tired of Outlook Express launching whenever you click an 
            email file or a forwarded message in IncrediMail, here's how to make 
            these .eml files open in IncrediMail automatically
            When you save a single email message in IncrediMail, it will be in 
            Mail format, and the extension of the file will be .eml. If somebody 
            forwards you an email as an attachment, the forwarded email will 
            arrive in just this .eml format. 
            Now, if you double-click on any of these .eml files (in Windows 
            Explorer, IncrediMail or elsewhere), chances are the message will 
            open in Outlook Express -- annoying if you use IncrediMail for all 
            your email and have made it your default email program, too. 
            Fortunately, it's easy to make .eml files open in IncrediMail so you 
            can happily double-click them and don't have to read forwarded 
            emails in a program you didn't ask for. 
            To associate IncrediMail with .eml files: 
            1.    Select Tools | Options... from the menu. 
            2.    Go to the Advanced tab. 
            3.    Make sure Associate '.eml' files with IncrediMail is checked. 
            4.    Click OK.