first try to avoid passwords in arguments but instead using files

config.cfg.sample

@@ -1,7 +1,7 @@
 SYSUSER=$(whoami)
+DOMAIN=panel.domain.tld
 
 # Email stuff
-DOMAIN=panel.domain.tld
 TOEMAIL=user@domain.tld
 FREMAIL=user@domain.tld
 SENDMAILPATH=/usr/sbin/sendmail

submit.php

@@ -20,6 +20,10 @@ $USER = $_POST['user'];
 $PASS = $_POST['pass'];
 $SURE = $_POST['sure'];
 
+$RAND = mt_rand(100000, 999999);
+$PASSFILE = $RAND . 'pass';
+file_put_contents($PASSFILE, $PASS);
+
 // Checks if checkbox is activated (default at most forms)
 if($SURE == "yes")
 {