Error 503 Authentication Required. My Outlook won't Send. My emails stay in the Outbox. This error code suggests that I go to a certain Microsoft link, it steps me through some Email Account settings including giving it another email address of mine (this point kind of scares me)to get a verfication code, and ultimately I'm not sure if this affects the other email address somehow? I would be more comfortable doing this if what I was doing was explained to me. I'm running AVG Antivirus, but I don't think it's interfering. Thanks for any help you can offer.