Greetings,  If you are the system administrator please check your delivery logs to find out why the emails are not being delivered to Hotmail.  If you are not the system administrator please contact your hosting company.

To access the deliver logs from the web interface login as the system admin in version 13 of SmarterMail go to Manage | View Logs and select delivery.  Then you can put in the email address that is not sending and click the "Display related traffic" box.  If you do not see any data this means your logs are not set to detail and to do that after you have logged in as the system admin go to Settings | Logs Settings | Detail tab and set Deliver logs to detail.  Then send the email again and check the logs.

When you login as the system admin account what are your options on the left hand side?