i found out the right answer (not to adjust text size on rotation !) Preserve HTML font-size when iPhone orientation changes from portrait to landscape
but being very naive to css how to use it inline ?
i used as follows, but it did not work
<html>
<head>
</head>
<body style ="-webkit-text-size-adjust: none;">
<font face="Arial" size="9";>< a href="mailto:subject= mysub&attachment=myatt.doc"> mail this< /a>< br/>< b>< i>Header< /i>< /b>< br/></ font>
</body>
</html>