I would do it inside the if checking results from the query.
if(mysqli_query($link, $sql)){
echo "Records added successfully.";
// ...............Do the email shit right here................
$emailsubj="subject of my email";
$emailsendaddress="
[email protected]";
$emailaddy2use="address I am sending to";
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/plain; charset=iso-8859-1\r\n";
$headers .="From: " . $emailsendaddress . "\r\n";
mail ( $emailaddy2use, $emailsubj, $emailmessage, $headers);
}