I suppose you're implying that Microsoft sold your new account name to spammers? It could also be that you used a name that you, or someone else, have used at a

I suppose you're implying that Microsoft sold your new account name to spammers? It could also be that you used a name that you, or someone else, have used at a different place and the spammers simply try sending mail to all the big email providers with that name in the hope of reaching someone. That would seem like a more probable explanation to me.