Managing personal Outlook.com account settings, security, and privacy
Changing your password is pointless because no one is using your account to send the messages. Create a rule that uses "Sender contain" and "Recipient contains" and specify your own address as the string its checking.
I don't have the options "Sender contain" or "Recipient contain". However I do have a similar "From" limitation to which I added my email address but unfortunately that does not stop the messages.