I'm developing an app that sends HTML mail. I just condensed all of my CSS code into a .css file that is now linked in the mail header:
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link href="https://example.com/mycss.css" rel="stylesheet">
</head>
<body class="email-body">
...etc...
I discovered a mistake in the .css file, re-uploaded it to example.com, and now for the life of me I can't get Mail to use it properly. Mail must still have the old .css file cached.
I know with Safari I can clear the cache with the Safari -> Clear History menu item. How do I do this in Mail?