Use thumbnail of email as URL Preview Image

Hi! I love Constant Contact! I find that I often want a thumbnail image of the first page of my newsletter to post on Facebook, on my website, etc. Its time consuming to do this on my own and I end up with a so-so image. I usually end up creating a jpg of the campaign and then using snipping software to just grab an image of the first page. I wish your software had a way to do this for me. Thanks! Kathleen