You are getting the sign in problem in Outlook because you have the same problem as everyone else on here trying to get Virgin to unlock their accounts....including myself.
If you try the Virgin website for your email you will get the text below...but its pointless phoning the number below or resetting your password as only a Mod on here is able to unlock it.
Your mailbox is not available at the moment.
Please retry again in one hour and make sure you are using the correct password to access your email from all of your devices.
If the problem continues, please call our team for help on 150 from a Virgin Media phone or mobile, or 0345 454 1111 from any other phone and select option 2. For details about how much it costs to call our team from a Virgin Media home phone,visit virginmedia.com/callcosts. Call costs from other networks and mobiles vary.