Why Borders Cause Problems in Dark Mode
Many email clients treat borders differently from background colors when Dark Mode is enabled.
For example:
Your email body background may switch to dark colors.
Your borders may remain unchanged.
White borders can become highly visible against dark backgrounds.
This issue is common in clients like Outlook.com.
Example in Light Mode
If you apply a white border on a white background, the border appears invisible. It looks like extra spacing around your content.
Example in Dark Mode
In Dark Mode, some email clients change the body background to dark colors. Borders may stay white.
This can create:
Bright outlines around content
Unwanted spacing effects
Poor visual contrast
Best Practice: Use Padding Instead of Borders
If your goal is to create spacing between sections, use padding instead of borders.
Padding creates space inside a container. It does not create visible outlines in Dark Mode.
Benefits of Using Padding
Improves Dark Mode compatibility
Prevents unwanted outlines
Creates more consistent rendering across email clients
How Knak Helps Detect Border Issues
Knak automatically checks for border issues during email optimization.
If a border matches the background color in Light Mode, Knak displays a warning in the Optimize tab.
Review Border Warnings
Open your email in Knak.
Go to the Optimize tab.
Look for Dark Mode border warnings.
Highlight and Edit Affected Sections
Use the available actions to locate and fix the issue quickly.
Highlight the Affected Section
Click Highlight.
Review the affected section in your email layout.
Edit the Section
Click Edit.
Open the styling settings for the affected area.
Remove the border.
Add padding instead.
Recommended Fix
To prevent Dark Mode rendering issues:
Remove borders that match the background color
Replace those borders with padding
Test your email in both Light Mode and Dark Mode
You can also review related documentation: Optimize Tab.
Need more help? Contact support via live chat within Knak using the chat bubble in the bottom right corner or email support@knak.com.