If you have a white background on your email, and you create a wide border around your content that is also white, in Light Mode it will simply appear as spacing.
In Dark Mode however, many email clients will turn the body background dark, while leaving borders untouched, so you will have a dark background with bright white borders. (As one example, Outlook.com does not adjust borders in Dark Mode.)
If you have added a border because you wanted to create some space between your elements, then it’s always best to use padding instead.
When you are building in Knak, we will warn you on the Optimize Tab if you’ve used a border that is the same colour as the background in Light Mode.
To view the affected section, click the ‘Highlight button. To adjust your colour, simply click the ‘Edit’ button, which will take you straight to the settings for the affected area so that you can change them.
To fix the issue, remove any borders that you have applied, and apply padding instead.
Need more help? Contact support via live chat within Knak using the chat bubble in the bottom right corner or email email@example.com