I'm having a few issues with my dedicated Windows server that has a Plesk panel: 1.) I can't send e-mail via PHP's mail() function, it always returns the following error: SMTP server response: 550 Requested action not taken: mailbox unavailable or not local Which setting should I alter in order to enable sending mail? 2.) The exec() and passthru() PHP functions don't work; their outputs are blank even when I try to run simple commands such as dir. Is there an option that I can toggle in the control panel to enable this functionality?