How do you attach images to email in ASP.NET based on user selection (not upload)?

I have an email form that's written in ASP.NET and is fairly simple. The user fills out the normal information (name, email, phone, etc) and then they can choose an image thumbnail (it's an advertising creative sample). When they hit submit the recipient receives the form with all the information and the name of the creative they selected but I would like to embed or attach the thumbnail for the recipient so they can visually see it in the email.

Clients are all on Outlook 2010 with HTML email.

No images are being uploaded (they are in a thumbnail folder).

What I'm trying to figure out is how to call that thumbnail based on their selec开发者_JAVA百科tion and embed/attach it to the email when the user hits submit.

Everything I've found online deals with users uploading images and doing it that way.

Thanks

Send the email as HTML, and embed it as an image in the email. Make sure to embed the full path, so the user can view the image from anywhere too.

<img src="http://www.mysite.com/images/creative/foobar.png" ... />