Attaching a file to email

I am trying to attach a local file from my C drive to an email process in page code-behind.  I am getting the error below and not sure why.  I have a FileUpload control that gets the path and filename and then I am using common asp.net code to attach and send the email.  If I do not attach a file the email works fine. Let me know if you need anything else to help resolve.  I am using system.net.mail process. 
Do I have to upload the file first? Thanks.
Could not find a part of the path C:\Grandkids\Grandkids 015.JPG.