How can I add an image to my auto respond email to clients?

I'm trying to include images in the auto respond emails, however I am only given the options to insert a source, an image description, and image dimensions. I am not sure how to use these tools to include an image. 

So far it is not possible to upload the image in the email wizard; however, I would suggest you to upload your image using the Image field, first add the field to your form and upload your image: 

Once you have uploaded the image go click on the image field in your form and go to the Image Source option on the top toolbar:

Then go to the email wizard and paste the link there, in the dimensions the first field is for the image width and the second one for the image height: 

Hope this helps.