I'm no expert on PHPMailer, but I don't think so, no. It sounds like you're just not authenticating. If you have IMAP/POP email set up anywhere (like on your phone) you might want to check your settings, or ask your sysadmins what settings you need. That said, if you're using Exchange you might not have SMTP available IIRC. I think Exchange has its own protocols and SMTP is only enabled on demand. Not something I've had to work with personally mind you