Is there a reason this responsive formatting is undesirable? This is likely caused by the width of the clients differing, with the iPhone being smaller than the droid and updating to the stacked format as opposed to full layout. You can definitely adjust at what widths the email will render different layouts, but i'd strongly advise against this unless you have a fairly good understanding of coding.
In my opinion, this responsiveness is desirable and as a reminder, you can always download the HTML and adjust the width of the browser window to see how the email will move responsive to the client width.
If you really want to correct this, you could reach out to a developer but keep in mind this email was designed responsive for a reason....