Question about Outlook Express

I am trying to take some of my "mts.ca" email adresses and turn them into alias emails, as i am now beign charged $5 per month for them.  when i try to do it, it will not work.  The primary alias on these accounts being a "mymts.ca" mailebox, with another alias being mts.ca, this was from before mts went with windows live for email.  When I go to verify the email that outlook sends to me, I get this message.  


This is the email that is being sent to the mts.ca box, but I log into the mymts.ca account to get it, as the mts.ca can not be logged into. 

regarding the primary alias, if i try to change it, i get this message.

Your organization's policies prevent you from changing your primary alias.

Ideas are greatly appricated.