Backup all MySQL databases and send to my E-mail

dbbackup.php

<?php
$DBUSERNAME = 'YOUR_USERNAME';
$DBPASSWORD = 'YOUR_PASSWORD';
$EMAIL = 'YOUR_EMAIL';

$boundary = '==DBBACKUP-'.md5(uniqid(rand(), true));
$date = date('Ymd');
$header = "Content-Type: multipart/mixed; boundary=\"$boundary\"";
$message =
	"This is a multi-part message in MIME format.\n".
	"--$boundary\n";
mysql_connect('localhost', $DBUSERNAME, $DBPASSWORD);
$result = mysql_query("SHOW DATABASES LIKE '$DBUSERNAME%'");
while ($dbname = mysql_fetch_array($result, MYSQL_NUM)) {
	echo "Backup $dbname[0]... ";
	$data = chunk_split(base64_encode(shell_exec("mysqldump --opt --complete-insert --default-character-set=utf8 --user=\"$DBUSERNAME\" --password=\"$DBPASSWORD\" $dbname[0] | gzip --best -f")));
	$filename = "$dbname[0]-$date.sql.gz";
	$message .=
		"Content-Transfer-Encoding: base64\n".
		"Content-Type: application/octet-stream; name=\"$filename\"\n".
		"Content-Disposition: attachment; filename=\"$filename\"\n".
		"\n$data\n".
		"--$boundary\n";
	echo "OK!\n";
}
echo "Mail to $EMAIL... ";
mail($EMAIL, "Database Backup ($date)", $message, $header);
echo "OK!\n";