Connect to both, and in the mysql_query() call, define which connection gets which query:
$conn1 = mysql_connect('localhost', 'username', 'password');
mysql_select_db('database', $conn1);
$conn2 = mysql_connect('otherserver', 'username', 'password');
mysql_select_db('database', $conn2);
$query = "INSERT INTO ihsreg (SubmitEmail, Bloom_Name, Pod_Name) VALUES ('noon@email.com', 'Bloomer', 'Podder')";
$res1 = mysql_query($query, $conn1);
$res2 = mysql_query($query, $conn2);