Hi blonde25,
For me to be able to assist you, please post your e-mail address. Also, please include the exact error message that you are encountering when trying to send messages.
As for the messages that were sent from your account to your contacts, I suggest that you visit the link to the Solutions post below. It gives information about the increase in reports that we have received about accounts been hijacked and spam mails been sent to customer's contact list without customer's knowledge.
http://windowslivehelp.com/solutions/safety/archive/2009/04/29/recent-reports-of-account-hijacks.aspx