Ask any AI coding assistant for an email template and you'll get something beautiful: flexbox layout, border-radius, rgba() colors, a clean <button>. Paste it into your ESP, send a test, open it in Gmail on your phone — perfect.
Then a customer opens it in Outlook on Windows and it looks like a ransom note.
This isn't the AI being dumb. It's the AI being too smart — applying everything it knows about modern web development to a medium where most of that knowledge is actively wrong.
Email clients are not browsers
Here's the fact that breaks everyone's mental model: Outlook for Windows renders HTML email with Microsoft Word's engine. Not a browser engine. Word. The same thing that renders your .docx files.
