Email account blocked and cannot send email eventhough I verified account ok

Hi - it started when my mail account on windows live mail was not syncing.  I had forgotten my password so I changed it via outllok and then removed account from windows live mail and re-added it.  But it would not sync...just said wait a few mins.  I began to read emails via oputlook and then noticed that when I tried to reply to an email it said "!We've noticed some unusual activity in your Outlook account. To help protect you and everyone else, we've temporarily blocked your account."  I verified my account via pin ok and can access my email but it still will not allow me to send from the account.  Help !