If people send you emails that contain formatting this means they contain html css code which dictates what you see. This has nothing to do with the theme you use. It's how they created/designed the email. It means you are choosing to view emails in HTML.

Only plain text emails lack formatting and therefore are usually a simple black text on white background or vis versa depending upon your theme and any other settings you have selected.

One option: choose to view everything as Plain Text or Simple HTML.

• View > Message Body as > Plain Text or Simple HTML.

However, if you want to override the formatting which all your senders have set up in the emails they send to you then do the following.

I'm assuming you are using the thunderbird 'Dark' theme.

• Settings > General
• scroll to 'Language & Appearance' section
• Click on 'Colours'
• Set 'Text' colour as white
• Set 'Background' colour as Black
• Do not select/uncheck 'Use system colours'
• 'Override the colours.....' Select 'Always'
• click on 'OK'

Thanks for your response!

Yes, I am using the dark theme. From my experience using Outlook and Google web mail, I've seen that dark themes can be applied to these types of emails, even if the sender has html code to dictate what you see. But I understand the limitation there.

I've done what you said with changing the color to black and changing the override to always, as I had mentioned briefly in my original post, but I wasn't happy with the high contrast highlights it puts all over the clients when I have it enabled.

I hope that in the future they will add native support for the dark theme to override the html css.

Thanks again!