First of all, it doesn’t just change by itself. There was a magical combination of keys that were pressed to make this happen. No, this one not something that a tech person would have done nor was it something that happened on its own. This is in fact a user error or something that was inadvertently pressed.
So, this may be that whole dark mode thing going on with the new Mac OS Mojave, right? Perhaps. And we’ll certainly show you how to lighten Mac Mail’s mood. Sorry, sad joke, but still funny, right?
Alright, here’s how to change the Mac Mail background back to white:
Enable Dark Mode in System Preferences -> General -> Appearance -> Dark
Then, launch Mail -> Use Command +, keyboard shortcut or click Mail then Preferences in the top left corner of the menu bar
Click the Viewing section and uncheck “Use dark mode for Messages”
Voila, you’re back using a white background in Mac Mail. Now, how can I make my dirty white keyboard that looks black now…back to white again. Do you I use a little water or Fantastic for this job? Ah yes, the job of a serious computer tech never stops.