<meta charset="utf-8">
<body onload="test()">
<form method="get" enctype="text/plain" action="mailto:one@example.org">
<input type="text" size="10" maxlength="40" name="subject" value="Fr&egrave;re Fran&ccedil;ois">
<input type="text" size="10" maxlength="40" name="body" value="Проверка">
<input type="submit" value="Send">
</form>
<script>
function test() {
  if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitForPolicyDelegate();
    document.getElementsByTagName("form")[0].submit();
  }
}
</script>