Gary, tagged.com is NOT included in Windows Live Messenger. It is a completely different service. The only association that I can find is that Microsoft has partnered with Tagged and some other social networking sites to allow users to transfer their contact lists to WL Messenger. However, that is by no means a requirement and it was not WL Messenger that created your tagged.com account. You should go to Tagged and see what you can do to get that account removed because it only seems to be causing you more spam e-mail.
Meanwhile, the best thing to do with WL Messenger is to block users except those on your contacts list. In the menu, go to Tools -> Options -> Privacy and check the box by "Only people on my allow list can see my status and send me messages". You can still get IM requests from people to add you to their contact list, but you can deny any that are from people you don't know.
WL Messenger does not generate e-mails nor is it a mechanism that will cause you to receive e-mails. You could uninstall it and you would still get messages that are initiated by the Tagged account.