(I found an answer or workaround on this forum to get SMIME to work through Outlook 2013 so I thought I would post this other problem I and others have regarding Outlook 2013 and Hotmail/Outlook.com aliases not working.)
Outlook.com/Hotmail aliases no longer work through Outlook 2010 (they used to) and have never worked through the new Outlook 2013. After testing it comes down to the server not allowing it. You can put the main Hotmail/Outlook.com account through Outlook as EAS or POP3, but aliases no longer work.
For all the testing and configuring see this thread:
and this thread: