Così?
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento senza titolo</title>
</head>
<body>
<form action="mailto:tuoindirizzomail" method="post" enctype="text/plain" name="form1" target="_self" id="form1">
<label>Inserisci la tua e-mail:</label>
<input type="text" id="t1" name="t1" />
</form>
</body>
</html>