Huge site icons in mail and RSS

When I have a post with a link where the link prreview is rendered nicely with the sites favicon, the site name, a preview image (social graph image) and a preview text this is a very useful thing.

However when such posts are displayed in RSS or forwarded in a email, the favicon-sized icon is replaced by a huge site image and this messes up the layout (especially for confusing favicons). Is there a way to make the email use the same small favicon or even turn off the preview feature in emails?