Description
If you use a width attribute in a email template, perhaps in a table <table width="600"> or image <img width="600"> that sets a width wider than the viewport, Samsung will make the email that width.
It adds an inline width to the <body> elements of width:600px and the same to the wrapping <div> element that Samsung include. These can be identified as #MessageViewBody and #MessageWebViewDiv. These can be overridden with our CSS but now they are also adding a meta tag
<meta id="meta-viewport" name="viewport" content="width=686" contenteditable="false">
This meta tag cannot be overridden that I have found so far.
The only way I have found so far to avoid this is to not use width attribute and only style with CSS widths. However this can potentially create issue for Outlook on windows.