Clean up HTML of email newsletter

I send out an email newsletter similar to the attached file. When the HTML in this file is displayed in a browser, it displays correctly. However when sent to a Yahoo email address, there is a white margin on the right of the header image. I would like the HTML fixed so that this white margin does not show when sent to a Yahoo address. Other than that, I do not need anything else changed at this time. I only want the very smallest changes that will correct the problem. I do not want the whole thing rewriting.