Etsy doesn't optimize their email marketing for many email applications - for example, I use outlook on my laptop, and most emails I receive from Etsy have overlapping graphic elements, photos that appear huge, etc.
Unfortunately I think the only thing you can do if this is the case is use a different platform (for viewing Etsy or other problematic emails), such as viewing the email on your phone rather than on your computer, or use the cloud-based version rather than your local email client.
